On the 23rd, I saw that the DL 1:00 flight running CVG-SFO was oversold. They were offering $400 vouchers for people to take the 6:30ish flight (I think that was the time, might've been 5:30). This was announced once over the PA, and shown on the DL flat screens as well.
DL also offered $50 upgrade from the non-cheapie fares (I think you LUser and even K class didn't qualify). This is some test market thing they're trying now. Elites trying to upgrade get cleared first, but they'll put a non-elite in a first class seat if they pony up the $50. They'll do that before they upgrade LUser fares, of course.
Actually, it's a neat trick. If they overbook the flight in coach, and there are empty seats in first, they're going to have to bump somebody. Might as well try to get $50 out of it.
(Edited to fix a typo. There's probably more, but it's late.)
[This message has been edited by ebell (edited 12-24-2001).]