In case anyone is interested, the Facebook video has a bit higher quality audio than the U2.com version. It's also 720p video compared to only 320p, though oddly the U2.com file is actually slightly larger. The Facebook 720p version looks just fine, even blown up on my 55" TV.
Details:
U2.com version
Video: H.264, 480x320 (letterboxed), 24 fps, 1523 kbps
Audio: AAC, 128 kbps
Facebook version
Video: H.264, 1280x720, 24 fps, 1488 kbps
Audio: AAC, 150 kbps
Hopefully they will put this on their official YouTube page soon. The audio and video bitrates are usually a bit higher.