Peak oil is not about the end of oil - it is about demand exceeding supply and thus the price goes ballistic. There will be fuel for aircraft for many years to come. The problem is that it will cost a lot more (unless other economic sources of fuel come on line) and this will increase the cost of flying for the average punter.
At least the high price provides revenue for the oil industry to develop new technologies for oil extraction and processing so hopefully in the next few years we will see a turn around in the cost.
Look at what the head of BP thinks the future holds.
http://business.guardian.co.uk/story/0,,1795824,00.html
TH