Congratulations. What a deal!! FYI, Priceline just recently signed United up with their program. In fact, it was just publicly disclosed today, but I'm aware of a couple other UA tickets issued by Priceline over the past few weeks.
Priceline's rules state that you cannot get FF miles on their tickets, but definitely ask when you check in. I've read about numerous people who've had Priceline-issued tickets on DL getting their miles, and even one was upgraded!!
Priceline's got a lot of naysayers today, but you just watch, some of those same people will start swearing by them.
The best Priceline deal I've ever seen was posted just a little while ago on the Yahoo Club I host to discuss bidding on airfares and hotels through Priceline <http://clubs.yahoo.com/clubs/pricelinedeals>. This person bid $99 for a 5 star hotel in Scottsdale and got the Camelback Inn. Their lowest rate on their website is more than twice that much.