I really dont think ASICs will influence USD prices for 1 BTC that much. But it will influence mining profit for sure !
Might have to stop mining with my GPUs because of negative profit ;-)
...I'll try to get some more BTC/LTC before this happens.
I also expect some ASIC / FPGA like hardware solution for scrypt coins to show up in the next months.
But in the meantime scrypt GPU mining sucks a lot more power than SHA256 mining (at least with multi-GPU rigs).

I really dont like scrypt so much because of the increased energy waste compared to SHA256 (I know about
the other advantages though...)