It's like a footrace, and once you are behind, hard to even catch up. And to take the lead is an even larger hurdle. While teams such as Ferrari, McLaren, Renault, and others work hard to catch up to the DDD cars, it must be remembered the DDD cars, especially the Brawn, will be also improving. Even if some teams close the gap, it will be changed when the lead cars also upgrade.
Right now, KERS does not really improve performance (at least when you look at just the lap times). Non-KERS are putting out very respectable lap times. But it's in the race, when defending or attempting a pass, is when KERS really makes a difference. As demonstrated during the Bahrain race, a slower car with KERS can hold of a quicker car without KERS. This situation introduces chaos and mayhem for the teams and drivers, but it sure gives us the fans one heck of a show.
People are different, and fans hold different opinions of what they wish to see in racing. Some consider it appropriate that the race should be decided on the quicker car and driver, without surprises upsetting the order of things. Others, such as myself, enjoy the intangibles, the surprises, and the changing of the guard. I enjoy watching a quicker car caught behind a slower one. Then my interest picks up, and I want to see how the car behind deals with the problem. That's what separates the men from the boys. That's what separates Michael from Ralf.
Getting back to the original question, the pace of devlopment will decide who's quickest at season's end, not what's on board. But if Brawn get what appears to be the most mature KERS, the Mercedes/McLaren system, into their car, look out. For them, integration of this system will probably be the easiest for all. And then they will have a car that is fundamentally correct, and with one of the best engine/KERS packages.
A proud Canadian, and yes, HOCKEY is our game.