Same here. Our organization has a large portfolio of domains (200+). I'm look to unload these domain names in 2013 either let them expire, sell direct or like you're considering, auction.
I have sold a domains direct, this was to someone that already had the business name. It was a high value domain name because their primarily a brand. But I didn't need to work to sell it. I've had people offer me money, but it's never been in the range I would consider.