There are so many rotations U2 could do. I've said it before but I'll say it again. Imagine if they did all of these:
Night 1 / Night 2
Pride / New Year's Day
Sunday Bloody Sunday / Bullet
Mysterious Ways / EBTTRT
One / ISHFWILF
AIWIY / WOWY
Desire / Angel
I Will Follow / Elevation
UTEOTW / The Fly
Of the eight above pairs, the songs serve similar purposes so it'd be very easy to rotate them nightly, some could very easily even share lighting and visuals. Any casual fan's going to be quite content with eight hits such as those. Then you've got your locks - i.e. Streets, and at present Beautiful Day and Vertigo. 7 or 8 new songs. And the remaining few positions can rotate fan favourites, from your well-known classics like Bad and UF to your forgotten gems like YBR and ES.
I guarantee you, if U2 did that, songs like WOWY, One, Pride, and Co. would sound a hell of a lot more fresh. It doesn't even cost you setlist cohesion or a loss of concert theme, since you're swapping like for like!