This would be amazing, but the only problem would be to connect those with IGNs. Sure, you can add a field that would pop-up when someone logs in, and ask them for the IGN before they would be able to post or do anything, but they can enter someone else's IGN, and get the tag before that person gets to register on the forums.
There would have to be a way to connect these, to confirm that someone owns the account. Maybe they could develop a system that would generate a random code for everyone, and then in-game, you would have to execute /register *code* from that account. Then the system would register that and connect the IGN with the forum account. ;)
@Tacosbefriends