Even if U2 somehow managed to pull out a Get Lucky-sized hook -something they've never done before - it's virtually impossible that it would be even half as big as get lucky. Firstly, they're a rock band, and rock (particularly if it's not unbearably terrible) is marginal these days. Rock bands don't have giant hits. There are exceptions, but they prove the rule.

Secondly, U2 are in their mid-50s, have been around for over 30 years, and already have a substantial number of songs clogging up the airwaves. Bands of their age don't have hits. They're old, and once you're old you're considered irrelevant. There are exceptions, but again they prove the rule.

The only way to combat the perception of irrelevancy is to go about their work and make the best record they can. If the record is good, people will likely respond (as long as you're already popular). Look at Bowie: after years of striving to be hip (and making an unheralded masterpiece in Outside), he gave up and focused on making really good records, and people got behind him again.

I think that the best that U2 can hope for is something like "Where Are We Now?" which was a number one, a song people love, but not something your average teenager would know or care about. As he was in their youth, Bowie should be U2's role model for how to go about their art. They should go about their business with dignified confidence and worry about nothing aside from making the best songs possible. That's unlikely though, because these days it seems like they're not satisfied with themselves unless 10 million people buy their record. This band would never have recorded the Unforgettable Fire, and without that there never would have been a Joshua Tree.