In the New York Times, there was an article in the Global edition Magazine named "32 Innovations That Will Change Your Tomorrow." Three of the innovations related to bicycle design.
Anti Theft Handlebars, bars that have some sort of locking mechanism that don't allow one to steer the bike all ready exist, like ones from Speedlifter. And so do options for a less greasy chain, like the belt drives from Gates.
There are lots of carbon fiber frames, but as far as I know it there are not any plastic bicycle frames on the market. And its definitely something we may see in two to five years. There are kids bikes like the ones from Firstbike, and I think the same technology could be used for adult bikes.
But importantly I think whilst the bike will evolve, to be sure the bicycle has a huge to play in our lives in the future no matter what form it is in.