I don't think so.

Soon there will be ASIC (probably not so soon the BFL ASIC's) but that doesn't mean that GPU mining wouldn't be profitable.

When ASIC reach a cheaper point and everyone can get one then theres next step in BTC. But the Difficult will only increase, pretty similar to the jump CPU>GPU mining.

Right now GPU miner won't drop, if they do the difficult would go down and GPU miner who don't drop will have more BTC.

Well that's what I think.