If they don't put out an album this year, I think they can kiss their 'unconditional-love' fanbase goodbye (although NLOTH already disappointed a lot of people). Putting out an LP in 2013 would mean they'd have released two records in 12 years. Not good enough.
Why do you keep saying this?
NLOTH disappointed YOU. Say it. Own it. But it did NOT disappoint "a lot of people".
Every article I've read recently stated how fans and critics LIKED NLOTH. It may not have been loved like JT or AB, but the way you write it is also incorrect.
Why didn't it sell as well? Heck, why isn't ANYTHING selling as well?
There are maybe 10 albums that are released each year that reach Platinum sales in the U.S. NLOTH was one of them in 2009. Only one or two reach 3x Platinum. Contrast this to 10 years ago where the top selling albums frequently hit 10x Platinum or more. Fast downloads have enabled people to download music so quickly that illegal downloads are now more challenging to catch. And the success of legal downloads, like iTunes, have enabled people to "cherry pick" their music. For example, "Magnificent" is one of U2's best selling singles on iTunes (in the U.S.). It's often in the Top 10 on U2 iTunes downloads (currently at #11). But the song barely broke the Top 80 on the charts. Close behind is "Crazy" at #13. Yet that song didn't chart in the Top 100 at all. The continued success of these songs several years after the album's release proves that people do like the music. But they either bought JUST those songs (and not the album) or were initially turned off from the album by GOYB (the same situation that occurred with "Discotheque" and "Pop"). But to say people were disappointed is incorrect. In fact, most fans feel "Moment of Surrender" is one of U2's all time greatest songs.
As for U2's release schedule:
1984-1990: 7 years, 3 albums (one of which is half-live) and a 4-song EP.
1991-1999: 9 years, 3 U2 albums and one collaborative album and a "Best Of".
2000-2009: 10 years, 3 U2 albums and two "Best Of" albums.
I'm not counting the many other collaborative songs, solo efforts, spin-offs, non-album singles, etc. U2 did during this time.
You can see what U2's basic trend is - they have been rather slow at recording for most of their careers. The only true quick output was early on - and that's for obvious reasons.
I understand your anxiety. But with a group as huge as U2, sometimes they do need to "disappear" for a while. That absence makes the heart grow fonder. Too much U2 and people get tired and bored and this leads to backlash. With U2 constantly being in the news due to the tour, "Spider-Man" and Bono's various charity efforts (and corresponding tax payments), I think a little less U2 was what the world needed.
If they can release an album either late this year or next year, the timing should be perfect.