I'm not sure he was actually in tears, but he was definitely getting emotional. He was really struggling to get those words out and trying hard NOT to cry.
I think this question of relevance is something that Bono (and probably the band) have been struggling with for at least 12 months now. Bono did an interview with The Age (Melbourne paper) last year where he spoke in a similar vein to this video, and while in Australia in his appearance on Oprah, he asked the question "does the world really need another U2 album?"
I have a feeling (as much as it pains me to say this) that he's starting to prepare for the end of U2.... which would obviously be a very emotional thing for him... and that when he talks or thinks about it, he get's a bit emotional.
Well that's just my humble opinion, I don't really have much to base that on.... anyway.... what do ther people think?