Originally Posted by Kyth

Probably not quite what you want but throwing it out there anyways:

Might want to look into PowerAuras (the issue will be the lack of a text display, as I don't think it has an option to display text. That'd be a nice feature for it, though.)

It has a "only in combat" option. You'd have to turn it on and off for raids, however. (I have it tell me when I'm out of range of our elemental shaman's totems, and always need to remember to turn that on each raid night.)