Click the Announcement about "New Offices" and you will see the mentioning about a MMO called "Project V13" :)

It was one of the rights they did retain, however they have a certain amount of time to start making it and then a certain amount of time to complete it or they lose those rights too.
I've been waiting for this, I guess it means they raised enough $$ to get to work on it, which Interplay said they had to do first.

Click here to see some interesting tidbits on what they are working on, via joystiq.

Yes that is actually a very old story, they where talking about a fallout mmo back in 2007.
I would like to see a sequel to baulder's gate that would be something else, hopefully they earn some cash with the mmo then they make BG3 in 2d of course :) realistic wish.

They don't have the rights to it. A Baldur's Gate 3 is in the works, anyway, as well as a conversion of the original unfinished BG3 into a free NWN2 module.

Well they mentioned some of their future projects (hopefully) :
"Among other projects Interplay has said it wants to develop are sequels to Earthworm Jim, Baldur's Gate: Dark Alliance, Descent, and MDK, provided it can find the financing"

You can find more information about the project here:
http://fallout.wikia.com/wiki/Fallout_Online_FAQ

I don't think Interplay owns the rights to the original IP any longer. If I am not mistaken, Atari is the only company that can do the PC version of the BG games now. Interplay, however, still owns the rights to the Dark Alliance Console games.
I, for one, am waiting for the "V(ault) 13" mmo and Earthworm Jim 4. Hopefully they don't go 3d with EWJ this time...