Pedrosa will be interesting if he consistently ends up looking at Stoner's exhaust pipe. His agent practically runs the Repsol Honda team (which was what ultimately forced Nicky Hayden out) and if things aren't going his way, the toys will come out of the pram.
He has to keep on the bike though. In the past, he has been far too crash-prone and when you only have 6 engines to get you through an 18 round season, you can't go filling them with gravel.
To be honest, I think Stoner could end up building a very big lead in this championship before the rest have had chance to catch up. This new gearbox on the Honda seems to be working very well (although I'd be interested to see how it works on slower circuits like Assen and Le Mans) and I can't see the likes of Yamaha really wanting to relax the limits on their engines to compensate.