I'm going to guess Sega picked it up. It's just not worth as much to anyone else.
Agreed. The value-add for Sega to hold it is probably more than it is for anyone else. The only other possibility would be if Sega hadn't qualified to participate in the auction and a holding company decided to bid on it with the hopes of licensing it out to them, knowing full well the value of the license in the hands of Relic or CA.