A late-year release date would come into conflict with the Achtung Baby remaster, which will likely be released during that very period to make it a true 20th Anniversary edition (the original was released in November), and I think we all can agree that it is going to be a BIG fucking deal in terms of marketing, reviews, etc. And it will also be perfect for Christmas gifts. No way they're going to have a new album compete with that.
The band has a five week break between the South Africa shows and their first South America show in Chile; from Mid-Feb to late March. Whether or not that McGuinne$$ quote was real, if the band is interested in keeping any kind of artistic momentum with this project, they really should be finishing the album during that time. And if they're already in the mixing stage, 5 weeks is more than enough. I just hope they don't wind up having to go back yet AGAIN to work on Spider-Man, a project that at this point must be sucking the creative life out of them.
After the South America shows, the band has a month break between the final Brazil show and their Mexico City stand, from mid-April to mid-May. That leaves a nice gap for a new album release precisely when Paul McG supposedly suggested. So if the band is done with their work by late March, that still gives the record company two months to get their shit together, which is certainly short by modern standards, but is enough.
This way, the band gets to practice more new songs during their 3-night stint in Mexico (if they haven't been previewing them earlier) to make sure they're streamlined for the U.S. shows, which are likely to be more scrutinized.
I can't fathom a scenario where the band would put out the album right in the middle of an American/Canadian leg. No way. And the idea that they would sit on it until AFTER the tour in the fall, or as far away as early 2012, doesn't make any sense either.