in many different online games i have played there was the option of not only dragging action to an action bar like ddo has,but also a "chain bar" which was a toggle bar that had 3-5 slots for actions to be put into. then that can be dragged to the action bar or mapped to a key. when you hit that key the whole chain would be used one after the other where actions that were still on count down were skipped.
i know that with the new clickies in enhancements there are just to many things to hit at the same time. and the keyboard is all so limited. the main reason i don't play a caster is you need like 6-9 bars open at all times.you cant see the game and need to have 15 more fingers. now this has come to the melee fighters as well.
and i think a lot of casters would also like the idea of not hitting each buff by itself. or chain spells they use.