IMO, there's no way U2 will release an album and start a tour "shortly" afterwards. They need their time to rehearse the new songs and I don't think they've ever started rehearsing before an official album release.
With NLOTH, they released in early March and put tickets for the tour up on sale shortly afterwards with the first concert taking place in June, so that IS a possibiltiy. I don't think they'd start a tour before June if they indeed released in March.
LOL at the "Bono is too fat" story. As if that would ever delay a U2 album
In fact, he seems to have lost weight and got into shape recently. What could actually happen is that he puts on more weight again over winter if they don't release the album now.
They need some promo activity, performances, tv appearances before Christmas! Even if the album release should happen in Feb/March, I still hope there will be a singe in 2013. Or at least a leaked one!