There is a really good reason to deal with nuts for single speed hubs. Unlike derailleur bikes, adjusting the wheel back and forth is necessary to adjust the chain tension. There is also the need to center the wheel side-to-side. (Remember, no near self-centering vertical dropout.) So, with a quick-release, you have to get both the chain tension and the centering right while the whole wheel is free to move. On a good day, easy. On a bad day, this can be very frustrating. But with nuts, you get close, tighten them then you can "walk" the hub in either direction by loosening one nut, pushing the front of the rim toward the appropriate chainstay, re-tighten and repeat on the other side. Sounds like a lot of work but you can do it completely brain-dead.

I see Scott mentioned this already. For the reason I just outlined, I will always have nutted fix gear hubs and would do the same on any single speed bike with horizontal dropouts or track ends. (Further plus: if you are riding and decided the chain should be just a tad tighter or looser, a quick, very accurate adjustment is easy. With a quick-release you are back to square one as soon as you release that lever.)

Ben