It looks like Las Vegas is getting another arena:

http://www.allnetllclv.com/

This seems like it might be more attractive to the NBA than developing a new market like Louisvile or Virginia Beach, or dealing with the logistics of Mexico City. This would allow Minnesota to move to the Eastern Conference as well.

Pacific - Golden State, Sacramento, LA Lakers, Portland, Seatte
Mountain - Utah, Denver, Phoenix, Las Vegas, LA Clippers
Southwest - Houston, Dallas, San Antonio, Memphis, New Orleans, Oklahoma City

Central - Minnesota, Milwaukee, Chicago, Indiana, Detroit, Cleveland
Atlantic - Toronto, New York, Brooklyn, Boston, Philadelphia
Southeast - Orlando, Miami, Atlanta, Charlotte, Washington

It may seem odd to split the LA teams, but realistically it only makes a difference of one game at most - with a 4/3/2 split, everyone in the five team divisions needs an extra game to get to 82, which for the Lakers and Clippers could be each other.