*cough* not much *cough*
McLaren/Mercedes will not the make the same mistakes they made last year, like letting Häkkinen drive... but neither David nor Kimi will be able to win the world championship, they will most likely compete in the top though. I would have to say Schumacher as the winner this year again closely followed by Montoya, the other teams are no good.
I guess that is the only setback with F1. FIA only lets the other teams race because it would not be as much fun without them, but in reality there is 3 teams for a total of 6 good drivers capable of winning, unless something spectacular happens. If you do not race for a good team, i.e Ferrari, BMW and McLaren your chanses of winning are very slim. And Kimi is definitely not overrated, Button was, but he still lacks the experience needed to be a champ...
I must say that I am looking forward to seing Mika Salo cruise around the circuits with his Toyota...