I'm probably going to hell for this, but... I actually don't think Whedon is that great a writer. I mean, sure, he has some great ideas. We have Whedon t thank for the basic set-up for Buffy and some of its better episodes, the basic set-up for Firefly and Dollhouse, and many of Dollhouse's episodes. However, the man has also written some monumentally stupid things. He gives characters inane and anticlimactic deaths, indulges in blatant and insulting geek self-hatred, doesn't think hard enough about big issues, and really sucks at writing long story arcs (which is why his shows keep getting canceled). And let's not forget that Whedon was behind Serenity (full disclosure: I hated Serenity and usually pretend that it never happened - "Neat, you have the Serenity roleplaying game?" "I have the Firefly roleplaying game; there was a printing error.").
I think Buffy without Whedon isn't as bad as, say, Sandman without Gaiman. It's more like Star Trek without Roddenberry. It might suck, but I maintain that it might be awesome. It might be awesomer than our wildest dreams. A writer, better than Whedon, might take Whedon's original ideas in a new and interesting direction. If it looks good in trailers and reviews, I might check it out.
