Here's what I think we could see in 2016, possibly into 2017. This is based on the logical prediction that U2 will do arenas in North America and stadiums in South America, Europe and Australia/NZ. Obviously not all these will happen, but they could happen, as in U2 could probably sell out all these shows.
North America arena:
NYC x 2 (an arena that isn't MSG, like Prudential Center or Barclays Center)
Philadelphia x 2
Washington DC x 2
Atlanta x 2
Miami x 2
Hartford (possibly x2 if no Boston gigs)
Tampa
Nashville
Cleveland
Pittsburgh
Buffalo
Detroit
Columbus/Cincinnati/Louisville/Indianapolis (only 1 show somewhere in this general area. I really hope this happens, as I live not far from all these cities)
Milwaukee
Minneapolis
St. Louis
Kansas City or Omaha
Dallas x2
Houston
Oklahoma City or Tulsa
Las Vegas x 2
San Diego
Los Angeles x2 (different arena, Staples Center or Honda Center)
Oakland
Sacramento
Salt Lake City
Portland
Seattle
Edmonton or Calgary x 2
Winnipeg
Toronto x 2
That's 40 possible shows in US/Canada arenas. Obviously not all of those will happen, but a 30-40 arena show NA leg is very doable.
Europe stadiums:
Lisbon
Madrid
One other Spanish city (Bilbao, San Sebastian, Seville)
Paris x 2
South of France (Lyon, Nice, Marseille)
Milan
Rome
One other Italian city (Florence, Padova, or maybe just a 2nd show in Milan)
Vienna
Zurich
Munich
Frankfurt
Hamburg
Copenhagen
Oslo
Helsinki
Poland
Athens
Former Yugoslavia area show (Sarajevo, Zagreb, Belgrade)
Budapest
Rotterdam x 2
Dublin x 2-3
U.K. - 4-5 shows (Manchester, Birmingham, Cardiff, Newcastle, London)
That's over 30 shows right there, which seems about right.
Latin America:
Mexico- 3
Brazil- 3-4
Argentina- 2-3
Chile- 1
Peru- 1
Columbia-1
Uruguay- 1
Australia:
Perth x 2
Sydney x2
Melbourne x2
Brisbane
Adelaide
Auckland x2
Asia arenas:
Tokyo- Possibly a series of 3-4 arena show
China- Beijing, Shanghai, Macau/Hong Kong
Singapore
Thailand
Manila
Dubai
We have roughly 100 shows here that COULD be done, but obviously they all won't. I can see this going into 2017 for sure, there's just not enough time in 2016. If they were younger they could do it in a year, but I don't think they will.