I have no doubts the ASIC miners will turn larger profits, but I don't think it will negate GPU mining at all..

The jump from CPU -> GPU in terms of hash rate (not effeciency) was almost literally 100 fold... the jump from GPU's to ASIC's is looking to be only about 10 fold.

In that a ~$300 cpu would get you ~5mhash OC'd to the max, a ~$300 video card would get you ~500mhash OC'd to the max, and these new ~$300 ASIC miners will only get you 5000mhash. In terms from the step up from CPU's it almost seems like a rip off... BTC's price saw a steady jump with the advent of GPU mining as it became more difficult and more $ was invested per btc turned out, in spite of the fact that BTC was still churned out at the same rate.... I think we will see the same with ASIC's.