U2's performance kind of annoyed me. 9/11 was a poweful and humbling thing and then we get Bono strutting around like he's God's gift to humanity soaking up all the applause. This annoys me enough at regular U2 concerts, but at the halftime show it bordered on inappropriate IMO. It seemed like to Bono it was more about Bono than the victims of 9/11, and that really got on my nerves. That wasn't a time for him to show off. He should have acted with more humility.
I can understand the irritation there, but in my opinion, I don't think it's quite one-sided - okay, sure, Bono didn't have to prance around the stage, presenting the audience with a glorified rockstar image. HOWEVER, the 9/11 tribute was U2's decision (originally Janet Jackson was set to perform the halftime show, but after a couple producers saw U2's performance at Madison Square Garden, they wanted them to perform... apparently, because U2's performance brought them to tears).
Now bare in mind, this was, after all, a football game, and the halftime show shouldn't be quite so morose, but rather a celebration, and I think that's what the band attempted to give (with, of course, a few melodramatic moments, courtesy of you-know-who). I don't know, I'm just not completely sold on the idea that Bono was purely intended on bringing the spotlight on himself - as is often the case with the man, his heart was in the right place (his soft-spoken prayer before the song kicks off), but I'm sure he doesn't mind the attention (him traipsing about the stage).
Overall, I truly believe U2 gave one of the best Super Bowl performances - not the best (that honor goes to Prince, IMO), but one that will definitely be remembered.