I think the key is here to have many players with the potential to be in that role. To me, that is what City have lacked this season - and honestly, I think it directly relates to the away form. There was no emotion unless they have the 40k+ behind them, they lost concentration and were unable to find the determination to come back from behind.
Having Kompany, Shay (both now blended in), Barry and Ireland in, who are all sounded out as candidates along with our young england captain Nedum, we have enough players all around the pitch to really shout and get the team going no matter what the environment or situation is.
After all, the captains band is just that, a band, and the personality is that matters. For the symbolic meaning, I would not give it to a new player however, but an old & established player who has spent at least some time with us now - Kompany. He isn't quite John Terry but with the others around him who have the same personality traits, does it really matter?