A wiki doesn't seem right either. When's the last time you've ever sat and browsed through a wiki looking for awesome stuff you didn't know about?
Wikis, imho, are a bit like search engines. They're great for collecting stuff that you want to find again, and they're great for finding stuff you're looking for. Blogs have something more - they point you to stuff which you never knew you could care about, they expand your interests. Wikis are a very clumsy substitute.
I think what's needed is perhaps an evolution of the blog format.