Relative to MT, I'm not sure TypePad is really an upgrade-- I thought of it as more a consumer turnkey version of MT for people who don't want to roll their own hosting. I guess it does have a bunch of interesting new features like the built-in photoblog and such.

I'm considering starting a little volunteer project to produce better-coded, more standards-compliant templates for LiveJournal. (Because 14-year-old girls need web standards too.) But I'd have to become a paying customer first, I think...