Was thinking last night; I can see this tour being the show they take to Australia, South America, etc. The problem in South America is that they can pretty much only do stadiums, there just aren't enough good 15-20,000 seat arenas in South America. So rather than modify the I&E stage to fit into stadiums, they could just take this tour down there and fill stadiums, and satisfy that market. While we haven't seen the stage yet, obviously, it's bound to be much less elaborate than the 360 stage, thus easier and less expensive to tour with in places like Australia and South America.
Australia/NZ actually have good arenas that would suit the I&E stage. Obviously the fans would prefer arenas, and that would probably mean 4 nights in Sydney, Melbourne, Auckland, and a few in Brisbane and Perth as well. But LN/U2 could determine that it's more PROFITABLE to take the rather simple Joshua Tree production down there and do roughly 10 stadium shows, play to more people and make lots more MONEY!
If they do this, it does not spell good things for SOE or I&E Tour happening in the near future.