2009 : WHAT WILL CHANGE EVERYTHING?

The tricky, slippery word in this question is "expect." There is nothing that I expect to see with 100 percent certainty, and there are some remarkable things that I expect to see with perhaps 10 or 5 percent certainty (but I sure would be excited if that 5 percent paid off). With that bit of preamble, I'd like to lay out my game-changing predictions ranked by order of expectation, starting with the near-sure things and ending with the thrilling hey-you-never-knows.

The real end of oil. Technology will make liquid fuels obsolete — not just petroleum but also alternatives like biodiesel, ethanol, etc. Fossil fuel supplies are too volatile and limited, the fuels themselves far too environmentally costly, and biofuels will never be more than niche players. More broadly, moving around fuels in liquid form is just too cumbersome. In the future, energy for personal transit might be delivered by wire or by beam. It might not be delivered at all — the Back to the Future "Mr. Fusion" device is not so farfetched (see below). But whatever comes next, in another generation or so pumping fuel into a car will seem as quaint as getting out and cranking the engine to get it started. 
Odds: 95 percent.

Dark matter found. The hunt for the Higgs boson is a yawn from my perspective: Finding it will only confirm a theory that most physicists are fairly sure about already. Identifying dark matter particles — either at the Large Hadron Collider or at one of the direct detectors, like Xenon100 — would be much more significant. It would tell us what the other 6/7ths of all matter in the universe consists of, it would instantly rule out a lot of kooky cosmological theories, and it would allow us to construct a complete history of the universe. 
Odds: 90 percent.

Genetically engineered kids. I'm not just talking about screening out major cancer genes or selecting blue eyes; I'm talking about designing kids who can breathe underwater or who have radically enhance mental capabilities. Such offspring will rewrite the rules of evolution and redefine what it means to be human. They may very well qualify as totally new species. From a scientific point of view I think this capability is extremely likely, but legal and ethical considerations may prevent it from happening.
With all that, I put the odds at: 80 percent.

Life detected on an exoplanet. Astronomers have already measured the size, density, temperature, and atmospheric composition of several alien worlds as they transit in front of their parent stars. The upcoming James Webb Space Telescope may be able to do the same for earth-size planets. We haven't found these planets yet but it's a shoo-in that the Kepler mission, launching this spring, or one of the ground-based planet searches will find them soon. The real question is whether the chemical evidence of alien life will be conclusive enough to convince most scientists. (As for life on Mars, I'd say the odds are similar that we'll find evidence of fossil life there, but the likelihood of cross-contamination between Mars and Earth makes Martian life inherently less interesting.)
Odds: 75 percent.

Synthetic telepathy. Rudimentary brain prostheses and brain-machine interfaces already exist. Allowing one person to control another person's body would be a fairly simple extension of that technology. Enabling one person to transmit his thoughts directly to another person's brain is a much trickier proposition, but not terribly farfetched, and it would break down one of the most profound isolations associated with the human condition. Broadcasting the overall state or "mood" of a brain would probably come first. Transmitting specific, conscious thoughts would require elaborate physical implants to make sure the signals go to exactly the right place — but such implants could soon become common anyway as people merge their brains with computer data networks.
Odds: 70 percent.

Lifespan past 200 (or 1,000). I have little doubt that progress in fighting disease and patching up our genetic weaknesses will make it possible for people to routinely reach the full human lifespan of about 120. Going far beyond that will require halting or reversing the core aging process, which involves not just genetic triggers but also oxidation and simple wear-and-tear. Engineering someone to have gills is probably a much easier proposition. Still, if we can hit 200 I see no reason why the same techniques couldn't allow people to live to 1,000 or more.
Odds: 60 percent. 

Conscious machines. Intelligent machines are inevitable — by some measures they are already here. Synthetic consciousness would be a much greater breakthrough, in some ways a more profound one than finding life on other planets. One problem: We don't understand how consciousness works, so recreating it will require learning a lot more about what it means to be both smart and self-aware. Another problem: We don't understand what consciousness is, so it's not clear what "smart" and "self-aware" mean, exactly. Gerald Edelman's brain-based devices are a promising solution. Rather than trying to deconstruct the brain as a computer, they construct neural processing from the bottom up, mimicking the workings of actual neurons.
Odds: 50-50.

Geoengineering. We may be able to deal with global warming through a combination of new energy sources, carbon sequestration, and many local and regional adaptations to a warmer climate. All of these will be technologically challenging but not truly "game-changing." It is possible, though, that the climate impact of our environmental follies will be so severe, and the progress of curative scientific research so dramatic, that some of the pie-in-the-sky geoengineering schemes now being bandied about will actually come to pass. Giant space mirrors and sunshades strike me as the most appealing options, both because they would support an aggressive space program and because they are adjustable and correctable. (Schemes that aim to fight carbon pollution with sulfur pollution seem like a frightening mix of hubris and folly.) Geoengineering techniques are also a good first step toward being able to terraform other planets.
Odds: 25 percent.

Desktop fusion. The ITER project will prove that it is possible to spend billions of dollars to construct an enormous device that produces controlled hydrogen fusion at a net loss of energy. A few left-field fusion researchers — most notably the ones associated with Tri-Alpha — are exploring a much more ambitious approach that would lead to the construction of cheap, compact reactors. These devices could in theory take advantage of more exotic, neutron-free fusion reactions that would allow almost direct conversion of fusion energy to electricity. The old dream of a limitless power plant that could fit under the hood of your car or in a closet in your house might finally come true. Since energy is the limiting factor for most economic development, the world economy (and the potential for research and exploration) would be utterly transformed.
Odds: 20 percent.

Communication with other universes. Studies of gravitational wave patterns etched into the cosmic microwave background could soon provide hints of the existence of universes outside of our own. Particle collisions at the LHC could soon provide hints of the existence of higher dimensions. But what would really shake the world would be direct measurements of other universes. How exactly that would work is not at all clear, since any object or signal that crossed over directly from another universe could have devastating consequences; indirect evidence, meanwhile, might not be terribly convincing (eg, looking for the gravitational pull from shadow matter on a nearby brane). I hold out hope all the same. 
Odds: 10 percent

Antigravity devices. Currentphysics theory doesn't allow such things, but from time to time fringe experiments (mostly involving spinning superconducting disks) allegedly turn up evidence for an antigravity phenomenon. Even NASA has invested dribbles of money in this field, hoping that something exciting and unexpected will pop up. If antigravity really exists it would require revising Einstein's general theory of relativity. It would also vindicate all those science-fiction TV shows in which everyone clomps around heavily in outer space. Given how little we know about how gravity works, antigravity or artificially generated gravity don't seem impossible…just highly improbable. 
Odds: 5 percent

ESP verified!Probably the closest thing I've seen to a scientific theory of ESP is Rupert Sheldrake's concept of "morphic fields." Right now there's nary a shred of evidence to support the idea — unless you count anecdotes of dogs who know when their owners are about to return home, and people who can "feel" when someone is looking at them — but Sheldrake is totally correct that such off-the-wall ideas merit serious scientific investigation. After all, scientists investigate counterintuitive physics concepts all the time; why not conduct equally serious investigations of the intuitive feelings that people have all the time? Everything I know about science, and about human subjectivity, says that there's nothing to find here. And yet, when I think of a discovery that would change everything this is one of the first that springs to mind. 
Odds: 0.1 percent