Anything devs code for ETH will run on ETC, right? So, the work devs do on ETH benefits ETC too. Even so, I don't see reason for the two chains to exist side by side. Ultimately the one with the most liquidity will win and, given ETH's head start, that would be my bet.
But, I don't have to bet since I now own equal amounts of both thanks to the fork. Pretty cool. I win either way.