I am a total newb, still haven't mined into double digit BTC yet.
Anyway wanted to chime in with my 0.02btc...
The slowness of mining on BTC made me take a look at the alt-coins, and afaict the majority of them use scrypt rather than sha256 as the mining algorithm. As far as I understand it, none of the ASICs presently (or soon to be) out there can mine in the scrypt arena, so while the proliferation of ASICs will make small BTC miners less profitable, I don't think they will make much difference to say litecoin or feathercoin.
If my lack of knowledge here is showing please educate me.
S.
If I may, to answer your question: Asics will affect scrypt based coin mining. As more GPU farms leave BTC mining due to the fast increasing difficulty, they will turn to mining LTC and other Alt-coins. So in an indirect way, asics do affect scrypt mining. I turned my farm from mining BTC to LTC 3 months ago. (I've been waiting for my 1.3 TH/s of pre-ordered asics for over 8 months.) There are some co-ops and new companies talking about modifying FPGAs to mine scrypt, but those projects look to be in the design phase. FPGAs don't have the ram or ram speed necessary to mine scrypt effectively. When someone works it out, it will be time for yet another pre-order party.