I just did a quick calculation and it appears litecoin as of right now with a ltc price of $.08390 is about twice as profitable as bitcoin mining... which would be where we were prior to the split.

Looking at litecoinpool.org the pool hashrate has gone up 50% since the btc split so its obvious everyone agrees that litecoin is where gpu miners will now be going as bitcoin ASICS won't work with litecoins and litecoin ASICs are not even being developed.

If i'm missing something crucial here someone correct me.. but at this time it appears that ltc is the way to go.