I'm fairly certain that Obsidian Entertainment (New Vegas, KOTOR 2, Neverwinter Nights 2) is making or planning on making a third Icewind Dale. I do know that Josh Sawyer, one of the lead designers for the first two, is currently working at Obsidian.
In addition, the guys who did Star Trek Online and Champions Online are doing an MMO-esque Neverwinter Nights game with a focus on player-created content.
E3 2011: The Next Neverwinter - PC Preview at IGN
I'm not quite sure how I feel about Neverwinter, honestly, considering the developer has a less-than-stellar track record. However if Obsidian's Icewind Dale 3 becomes a reality, complete with Josh Sawyer spearheading the project, I could be a very happy man.