It all depends on who will develop it. BioWare is probably out of the question, since they're already developing TOR and two other games. Same thing goes for Obsidian, though I'm curious on what Avellone's take on an MMO would be.
Either way, if there is going to be another DnD MMO, I'd base it in an unfamiliar setting, instead of the redundant Forgotten Realms. Planescape or Al-Qadim comes to mind,