I've logged in a few times. It's an interesting concept, but I think the Second Life aspects are going to be pared down significantly, to get them out of the way of more "real" interaction. I'd be satisfied with just the titular Home space, if I have the ability to invite friends list members in for avatar-based text or vox chat while we figure out which game to play together. Adding some PSN game sharing (like the PSP PlayShare) would help make it more social AND likely spur more sales of DLGs.
I'm glad Sony's still working on it. It's free, after all, and still technically in Beta, so expectations should be kept rather low. I still see plenty of ways this could grow into a very interesting alternative to the far right option on the XMB.