Word on the street is that one of Hiroshi Sugimoto's images will be used on the cover.  I am guessing it will be one of these http://www.sugimotohiroshi.com/seascape.html

I am guessing the one title The Lugurian Sea.  I am hopeing Four5One adds some color....the original reminds me of ATYCLB and Boy with its b&w color scheme.

Here is the original source: http://blog.art21.org/2009/01/14/sugimoto-u2/

This would be a lovely cover. Keep the typeface low key and simple, no other colors, just the image, title, name of group. Period. Work of art. Yes.

Niiice 

That would make a great cover . very Joy Division in its look . anything would be better than the band shot of the last album, come on U2 be brave and go for something different and adventurous to reflect the music we hope .

I think those pictures are too plain, bland, and boring...but that's just me

Boring,  would be what the cover was with the last album.   ...Something creative,  different.   We don't need a shot of the band.  Name, and title of the album would suffice

When I hear the words No Line on the Horizon, those pictures are "exactly" what I think of...it's too predictable...I'd like it to be a bit more abstract

I agree,  having said that,  I'm not so sure the album covers really truly matter in this case.  I'm more concerned about the sound.   The last two albums were good in their own sense but nothing great.   I want something that will blow my mind away!

HTDAAB's album cover was hurendous.  This is classy!!!!  I agree with the above comments.  Low, non-intrusive text and that's it.  It allows imagination to the viewer as to what's in the album and what kind of mood it might be inside........HTDAAB's was........just four guys sitting there.....I really hope they go with this........again, it let's you imagine what the mood of the album will be.

Go back to something creative, like Achtung Baby, or the unforgettable fire, where it really didnt include any members of the band.   Except for the Achtung baby where we can see a nude Adam

I'm really digging this!

Actually, I think U2, in the spirit of breaking into some new level of artistic ground, ought to use one of the aforementioned pics from the first post.

I'm getting an instantaneous Joy Division vibe...
If it's not the most aesthetically pleasing cover photo, so what?

The biggest band in the world can do whatever the heck they want...

These sexy boots were made for walking,
macphisto

I don't think any of those pictures are really groundbreaking though...

The top picture (Caribbean Sea, Jamaica, 1980) is just an ocean...and there is definitely a line on that horizon

The middle picture (Ligurian Sea, Saviore, 1982) reminds me of Nine Inch Nail's "Ghosts I–IV" album cover...and Bon Iver's "For Emma, Forever Ago" album cover

I know niether or those albums covers are exactly the same...but they just seem like they have the same sort of vibe and atmosphere

And then the third picture (of the Baltic Sea) is just black....and that's been done lots of times before

It has nothing to do with aesthetics...it's just I'd like something that's never been done. Before Achtung Baby came out, I don't know of any album cover that resembled it

I'm not trying to sound like a jerk or anything...I know what you're saying  all of this is just my opinion...either way, as long as the music is good, I'll be happy! 

I think it would look better if it was more colourful. I think they look a little too easy and predictable.

The more I look at it, the more I like it.  It lends itself to so many different perceptions.  I could look at it and think one thing, you may look at it and think something completely different.  You can't say that about their last two album covers which were ok I guess.  HTDAAB is less apealing now then ever, maybe becasue it's not one of their best albums.  I don't know, but I really like this choice.

It seems to ask:  "What do you think is inside?".......it's almost like a tease.....maybe I'm reading too much into this.