Until they figure out what to do with it they should put in a simple musical review show based on British bands. Call it "The British Invasion: LIVE" or something like that.
As far as Toon Lagoon Theater, with the lack of kiddie stuff at IOA, a rubber head show would be better then an empty theater.
I mean, even 6 Flags has both of these kinds of shows so it shouldn't be a problem for Universal.