I've been using the Vibram Five Finger shoes this Summer as a descent shoe. These things kick ass! They're super lightweight, low profile (I've tested them in squeeze chimneys :), comfortable, and no-compromises coming down steep trails, easy slabs, etc.
Heck, I even prefer them hiking up and down to the base with a heavy pack. They suck for cragging though, as they are a pain to get on/off frequently.
I'm not one of the folks who is going to run 50 miles in them, but as a descent shoe they're awesome. Just get the kind with a burly sole. I'm going on my 15th descent with them this summer, and still no sign of blowing out. One descent involved at least 3 miles of hiking - no problem.
I'm done with clunky approach shoes clipped to my harness! They're as light as flip-flops, but absolutely solid on the way down.
Agreed Andy I have been using them on the descents in the Black Canyon, and they work well, and are super light for the climb back out. My only complaint is that I have sort of destroyed them. Are yours holding up well?
Mine have lasted through 15 descents. I don't expect to get more than a summer's worth out of them - but that's good enough for me. Heck, my normal descent shoes barely lasted much longer.
Here are the ones I got. They were the "burlier" ones at REI, for what that's worth:
I also find my knees much happier, as you naturally descend on the balls of your feet, rather than the heal strike. Much less chance of rolling an ankle too - since your foot isn't elevated by the thick sole.
My wife was skeptical, but got a pair - and she also now prefers them - and she is a very cautious "descender".