That's not gonna happen. Brawn GP, Williams and Toyota have a design advantage in their diffusers. It will take a few months at least for the other teams to redesign their cars to match because everything is so tightly packaged and integrated. Then again, the diffusers may be deemed illegal before then so that would bring those 3 teams back down to a more level playing field.Probably by the next race Mclaren and Ferrari will have caught up with the other teams in the design area and be back at the top.
Next race? Not a chance.