I mentioned yesterday when the new broke on this year's winners of the Physics Nobel Prize that this was not a surprise at all. Someone at work asked me about that, and I told him that Geim and Novoselov were listed #3 in a recent poll in predicting this year's Nobel Prize winners. One could see this coming years ago.
The Nobel prize, and certainly in physics, is all about discovery (read its charter). So discovery of something as important and rich as graphene was a no-brainer to be awarded the Nobel Prize. It was just a matter of time. This is also why I predicted topological insulators to be in a similar situation a few years from now, if not sooner.