Re: External Blogs
No one can answer on Nicola’s behalf, but it sounds like he’s abandoning development on this project to me, in lieu of it being a core feature eventually.
This would work not unlike the way wordpress.com allows you to map your blog to another domain. I suspect that would basically end up being this, or vice versa? That being said, it sounds like a WPMU feature that would have a piggy back panel for BuddyPress to me.