Okay, listening again, and it sounds less like Bono.
Is it Edge? Someone else said they thought it was him, and now that the thought is in my head, I can't un-hear it.
I haven't heard Edge singing on enough songs by himself to make the call. I know sometimes he and Bono can sound similar.
It would still explain the "wink wink nudge nudge IRISH SONGWRITER" note, and, as EdgeFest posited elsewhere, would make more sense considering they're talking about sitting around playing guitars.
Edit: although in the iTunes notes, it says songwriters are Andrew Fariss and Bono. Not sure if that was in the original track, or if someone added the metadata before uploading it and spreading it around.