Look at the companion thread to the review of Golite Carbon Fyre shoes, here:
I'm still wearing my original pair of Sun Dragons for walks around home, etc, looking to see how and how fast they'll continue to degrade --- they're not pretty, but I'd guess I have a good 400 miles on them and they're still entirely useable. I'm starting to run/walk in a new pair, and still plan to thru-hike the PCT wearing this shoe in 2008, with fingers crossed that Golite sufficiently corrected the problem that they'll be durable enough to get good mileage (perhaps 600 miles per pair?) out of them.
Another shoe isn't really an option for me --- I found this year that I really *need* the wide toebox that these offer, else I get various front-of-foot problems. And besides, they're so comfortable!