I'll disagree on that comment. The poor schlub who has to get gouged and buy a last minute Y ticket deserves something! Look at it this way, CO restricts it to elites only. NW has the ConnectFirst program, where if ANY customer buys a full Y and connects thru a hub they get upgraded immediately!

I had a problem with CO trying to make me buy an F seat earlier this year. They wouldn't honor their "Guaranteed Y seat if booked at least 48 hours out" benefit for elites. I was told that because there were still F seats available for sale, that I would have had to buy one of those. I flew NW instead, got the upgrade at time of ticketing. Had to go thru MEM, but since $1000 to CO for a Y seat IAH-PNS wasn't good enough, I gave the money to NW instead.