With various suggestions coming up regarding cross server functionality, I'd love to see a global Looking for Group.
With the current player base, LFG should be a viable option for finding groups. But with players spread across servers it can still be difficult.
Ideally the system would gather people together on one central server for the instance and return them after. Barring that, it could it could inform the player about a group and give them the option of automatically changing servers and joining.