Other then being able to move things around, really the most important thing I hope/wish/pray that I could do is to unhook my portrat (sp) and the target portrat so I can move them off my hotbar and around the screen.
Secondly, I really wish I could set up my hotbar to look like this...
XXXXXXX XXXXXXX
XXXXXXX XXXXXXX
It would be easier for me to group things together the way I want, thus givig me easier acess to my abilities.