U2 should just run the ball! Er.... oops, I'm on the wrong board. :-)
No really, keep it simple, Songs of Ascent should have no press, no single release, no radio push... and no known release date, nor should it be made available online, just have it show up in stores unannounced, and let it build up from the ground up. And tour in front of it.... start playing those tunes on the next leg before it gets out, let the concert be the leak, not the internet.