I'm looking forward to this. The official stance on it is that it's not meant to replace tabletop gaming, it's meant for times when getting everybody around the table would be impossible.

This means that those with young children won't need to find a sitter to still play with their friends. And hopefully this'll allow friends from around the world to play together too. I've got lots of friends who like D&D and tabletop roleplaying, but they're all over the net, getting them together for a game would be swell.

My main concern is the pricing. WotC has previously announced that a subscription to D&D Insider will be competitive with MMOs, around $10-$15 per month. If that allows for the DM to set up the virtual tabletop and invite non-subscribers to play, then I'm in. If that requires every player have a subscription, then I'm out.

(On another note, WotC has stated that other parts of D&D Insider that aren't 3D will probably be platform-agnostic. These might include a web-based character generator, and (defective) PDF copies of RPG books.)