There is a great market for that. Sparklit (http://www.sparklit.com/) has a hosted product (which looks might be derived from vbulletin), for example, but pretty much everything out there I've seen is old (1.0, as you put it). There is lots of room for innovation.

Data portability is still a huge problem. There is a massive lock-in once you get a forum going on a hosted platform because it's such a pain in the ass to get everything out.

I've considered rolling my own, but decent forums are deceptively complex. It would take way too much effort.

Go for it.