I think Mercedes would be stupid to let Ross Brawn go. However, perhaps these rumours have stemmed from Ross Brawn willingly wanting to step down. He has been in F1 for many, many years now, and perhaps he is trying to build the team up, with the right people before he steps down himself?
As for McLaren, I would hate to see Ron Dennis back as team principal. Admittedly, I am more of a driver supporter, than a team supporter, but McLaren have been much more likeable since Martin Whitmarsh has been in charge, than when Ron Dennis was. Obviously, winning is more important to these people, but with Ron Dennis in charge, the team wasn’t that much more successful anyway, at least between 2000 and 2007 in terms of Championships. Ross Brawn, however…I would like to see him there, if he is being forced out of Mercedes, just because I think he could be a key asset to the team that has just lost a key member of staff.