I'm listing the things I feel are the biggest needs at the moment and needs ot be put in ASAP.
UI customization/addons
1. I want to be able to resize and move my interface frames 100% freely.
2. Need one more bar.
3. Need a procwatch-addon ala PowerAuras from WoW.
4. Better healing frames, be able to see relevant buffs/debuffs more clearly, HoT timers and the like.
Companions
1. Smarter AI, it should know when to not use AoE abilities that are on auto, if it will break CC.
2. More responsive to commands, they need to react faster when I order my companion to attack.
Grouping
1. A proper group finder, I'm thinking a refined version of the older version in WoW (before the auto-group/cross-server one).