MLS expansion to 20 teams - New York Times article

According to this article from the New York Times its quite possible that within a few years MLS could expand to a total of 20 teams. Currently the Seattle Sounders will begin play next season and the Philadelphia team the following season. It has already been announced that 2 more teams will be added for the 2011 season and now it seem that MLS might add 2 more teams on top of that.