Ok, from what I can tell most ppl here (in the thread) seem to like the idea - I do to - what seems to be standing in the way is a fear that it will be abused in some way by everyone deciding to vote for the same person (for some reason).
So, how about you don't get to vote on every person?
Say, after the battle each player is presented with an individually randomized list of 10-20% of the combatants (evenly distributed from both sides) and you get to pick 1-3 red and 1-3 blue from that selection?
Most votes gets the prize! (for starters it would be something symbolic, but if we notice it works there might be real prizes down the line)
If you want to complicate things you can add an implicit negative vote, so that each player not voted on by a player (cause they chose someone else) gets a negative vote of 0.1 (or something). I'm not sure of the effects or neccesity of this, but I sense it will prevent a person winning cause they happened to have their friends online and getting them in their list.
/Edlit