I'm totally for keeping CGMiner as simple as possible. I actually wonder if one day you will drop GPU support for strictly ASIC support. However, the higher performance of native cuda seems to be pushing the cards into the realm of slightly profitable. A 580 seems to push 280KH/s, which is about $1.25/day profit.
I'm curious as to what miner this would be where they were able to get 280 out of it. As I'm one of those poor bastards trying to make just 1 BTC on my 670 with a profit of ~$0.30 - $0.50 a day