This isn't a suggestion so much as my opinion on what makes a truely great MMO. I just need 4 basic things done really well.
1. Fun Battles.
2. Comradery.
3. Epic Loot.
4. Engauging Storylines.
I just ask the devs to take these core elements in mind at all times. When wanting to implement something, ask themselves is what they are trying to accomplish going to fit 1 or more of these core elements.