Haven't watched the last couple episodes yet so I may have missed something important, but with Ed Helms suddenly becoming a giant star thanks to The Hangover, why not promote him in some way? I think he's the show's biggest star after Carell, no question.
I would be willing to watch The Office w/o Steve Carell. They just need to do it right. They can't put in someone else with the same character, that would be terrible. They need to create someone new with new character quirks.