I've had my '10 Roadster since April, and I sat on an '11 one at the NEC bike show in Nov. I couldn't see any changes apart from the colours, and the footrests are just the same. I don't think Triumph have done anything for '11 except use new colours - as they had just dropped the price when they launched the Roadster ( in the UK anyway) they won't be spending any more on changing it until they have to.
Go for a '10 and save some dosh that will buy you TORs, a straight through crossover pipe and use Tune ECU to re-map. If you haven't worn out a rear tyre by 3000 miles you don't need any more power!
I'm taking mine to a track day soon.......Knockhill