i just wish they would take some action bar UI functions from aion. when you use the initial action to start a combo, the next action in the combo would pop on the same slot. so you could do a 3 hit combo by mashing 1-1-1 instead of say 1-2-3 so you can set 2 and 3 as other abilities if you want. and, reaction ability's would light up after you met the conditions. i.e.: if you parry, the ability that needs a parry would flash up a bit to let you know you did. instead of trying to pick out the text.

edit: i don't know if aion came up with these or anything like this, they just used it and i liked it