This small addon raises the hotkey text above cooldowns, flashing borders and other stuff like OmniCC.
The upshot is your hotkeys always appear topmost on action buttons.
From this thread: http://us.battle.net/wow/en/forum/topic/12673197448
It's Fenril-Whisperwind's idea, I just supplied the minor code.
After testing it for a bit, it's a nice subtle effect and maybe others will find it useful too.
Action bars supported: