Consider mining LTC. GPUs are the only viable option for mining scrypt coins at the moment, and it doesn't look like that will change anytime soon.
A lot of folks, myself included, think the value of LTC could explode in the coming months if and when it hits Mt. Gox.
Also, mining LTC and trading for BTC has historically been more profitable than mining BTC directly.
Mining LTC is not more profitable right now. And it will only get worse as more GPU miners switch to LTC.
And MtGox will NEVER trade LTC.