I've played a few NWN2 persistent worlds before. In fact, I was on one just last night!
The RolePlay tab has quite a few - and if you sort them by users you can generally find the best ones at the top. As I recall the Baldur's Gate one is one of them - 3rd or 4th when I last checked. Other tabs have various games that may be of of interest, such as the Social tab. Though, beware that most of them are just a center for adult content, and the top-most one you should avoid like the plague.
http://forgottenrealm.ca/Was the top-most one when I was playing last night. Seems like a good-enough server, with good enough DMs. Didn't stick around long (was lagging very badly), so didn't get a strong feel for it, though.
http://dragoncoast.orgAnother good one, it looks like. I'll probably be trying this one next time I jump into NWN2.
All in all, I say try it out. Go on - it's very much like an MMO (guessing - never actually PLAYED an MMO for more than a month, and only once that long), only on a more personal basis (dozens of players instead of billions), and no annoying monthly fee.
Edited by Michael, 20 February 2009 - 12:08 PM.