If you already have GPU mining rigs, I assume you (and most people) will switch to Litecoin. In the past few days it's actually been a bit more profitable to mine LTC and sell for BTC then to mine BTC directly. And there are also a lot more Litecoins that can be mined. We just have to keep the interest of people like you a bit longer so that more services can be developed.
Just curious, how difficult is it to modify a ASIC rig to mine LTC?
I suppose there's always the possibility of a new xyzCoin based on different hashing algorithm(s), which will screw the ASIC?