I think the "association" is partly because it will mostly cover football, and the other sports are probably fine as separate conferences (especially for travel costs).
It will allow them to consolidate TV rights and Bowl bids. I suggest that NBC Sports is behind this move. They already own the .mtn network and the Conference USA rights are up in 2016 from FSN and CBS College Sports. It won't be big money for the schools, but it will be better than they can get on their own since both conferences have lost their "top dogs" for TV ratings over the past two years.
Fresno, East Carolina, Air Force, Hawaii, Southern Miss, and Tulsa will make the top end of the conference look decent, with any team going undefeated still possibly being a "BCS buster" if that format still exists in the future.
I would bet that the divisional format will mirror the current conference alignment with maybe 1 cross-divisional game scheduled per team per season, and a conference championship game hosted in JerryWorld for the two division champs.
I don't think this really adds to the travel budget than what most of these teams were going to be facing anyway. Hawaii is not going to be playing multiple games in the eastern time zone each year.
In basketball these leagues needed to consolidate after losing some of their upper tier as well. If they also consolidate the hoops then they can look to retain higher RPI and more tourney bids each season (which means more $).
Utah State and Louisiana Tech are probably hoping to jump ship into this league rather than face complete obscurity in the WAC.
Maybe the SunBelt and WAC will be next to announce a merger or association to stabilize their membership.