It's still worth it imo.
It's gonna be some time still before asics hit the market, and even when they do, they'll only be about twice as good hash per $ and not 10+ times like with sha-256.
ASICS already hit the market, check out the dual USB mining... They are now mass producing it and in 1-2 months you should see it flood the market..
I don't know if this is the case. If you bought 10 of them you could save about 200 watts on power consumption over a 7950. At $0.10 per kilowatt, you're looking to save about $175 a year. The price difference on hardware is about $500. It will take about 3 years to break even on that. Not to mention, you can resell the graphics card and make additional money. ASICs, not so likely.