I don't blame Rosie for leaving. It's the right move. She was too big a force for that show, and there are far less-restrictive ways for her to get her message out there and express herself. She's already got a blog with a thriving audience, so even when she leaves TV, she'll still have a public platform.
My guess? She'll join Howard Stern at Sirius satellite radio for a HUGE bundle of cash. She'll have flexible hours and who knows, maybe she'll even set up a studio in her own home and do the show from there. Radio would allow her the luxury of not having to do the whole hair and makeup thing, and she'd be able to state her views without being censored.
Whatever she decides to do, I'm pulling for her. Good luck, Rosie!