Look I am not gonna pretend I've read the whole thread on this, is 8 pages and I just need to point out one thing:
In WoW you have 3 DPS 1 tank 1 healer for dungeon and the DPS ques might be even longer than they are here, and in WoW you can Que as multiple roles.
Adding 1 DPs spot is not going to make things faster.