A guy who is 41, 7 time World Champion wouldn't return to a sport which he dominated for pretty much a decade without knowing he can deliver, and I really think he can, and if he does and it's Michael of old then the likes of Lewis, Vettel and Button and so on need to raise their game, because this year nobody was on it all the way through, there were mistakes and things that happened due to pressure, car issues and such that MS has suffered in the past but dealt with in a way where his performance was supreme, he dealt with it.
The problem that I have with MS returning is that he has been out of the sport for 3 years. I remember when Prost took 1 year out in 1992, Senna commented that this was a VERY brave thing to do and that he would never do something like that as he would probably lose some speed. When Prost did return, I always felt that he wasn't the Prost of old and seemed to have lost some of his race pace (in qualifying he was decent, but during the race, D.Hill seemed to have the edge). Prost did quit F1, later that year.
As far as I'm concerned, the Jury's out on whether or not MS can perform in the same way he used to.
With regards to the young guns having to raise their game to compete against MS: MS was beaten in 2005 and 2006. He quit at exactly the right time, I think, where Alonso had now taken over his mantle. I can't help but feel that in equal cars, in 2010, MS would finish behind Alonso and Hamilton. In 2005/6, MS was past his peak and in 2010, I can't see how he could've improved, to enable him to compete against Alonso or Hamilton.
I'll say this: MS is the most complete driver I have ever witnessed, by a big margin, but at 41 years of age, with his best years behind him, having had 3 years out of the sport, having already been beaten in his last 2 years in F1 (by Alonso) - in 2010, I can't see how he can compete with Alonso or Hamilton...unless he has the best car on the grid, by a big margin.
I could rant on about this for hours as it's my number one sport and I have a MASSIVE amount of passion for it, and not just MS returning, F1 in general, but I'll stop now and give you all a break lol.
Please...rant away, this is a forum for motorsport fantatics. And normally during the closed season, only the hardcore F1 fans will be hanging around the F1 threads, so these threads will be thoroughly enjoyed by those who visit them.