Nuclear power currently is the only real alternative to fossil fuels and is being used in many countries at the moment. Developing the technology further will improve efficiency and add further reason for increased use of nuclear power.
In addition to Nuclear power, Geothermal, Hydroelectric & renewables such as wind and solar can be used to replace some of the fossil fuels.
An interesting question, as both oil and nuclear have had a bad year in terms of high-visibility accidents. I’d expect that investment in all sorts of renewables (wind, solar, wave, geothermal) and biofuels might increase over the next few years. The high oil price means that other options may not look so expensive as they were in the past, and makes them more attractive to investigate. Whatever the outcome, I imagine the best outcomes would be firstly to have a more diversified energy sector (to spread the risk), and secondly to do a lot better at reducing consumption.
Good question. I think electric cars are the way to go, although it would take a lot of effort to convince political decision-makers and to change the infrastructure to accommodate for them. I am a skeptic as far as biofuels are concerned, because I really think it’s better to eat that stuff than to put it in our cars! In general, we might have to learn to get around with less fuel, like using more public transport, buying locally, and cutting down on long-distance flights.