From Strategypage.com
The U.S. Army is moving ahead with a major reorganization to make the brigade the major combat unit, with the division replacing the corps as a headquarters. Details of the new organization are not yet set, but active duty combat brigades will probably increase from 33 to 48 and reserve/National Guard combat brigades from 15 to 22. This makes available some 60 combat brigades, but only about 140 infantry and armor battalions. That's because the new plan calls for frequently using only two combat battalions per brigade. The idea behind that is to mix tank and infantry companies more frequently, and regularly. This is an idea that has been bounced around for decades, because in combat, you often have tank battalions broken up so the tanks can operate with infantry units.

This is, IMHO, a rather poor idea to increase the number of deployable brigades. It dramatically reduces the "speartip" portion of the forces by cutting the number of maneuver battalions from 3 to 2, while adding combat support functions. Instead of five mini-brigades under a division, it might be better to increase the number of maneuver battalions to four, add several support battalions depending on mission, and abandon the increasingly outdated division structure altogether. This was the recommendation of Colonel Douglas Macgregor Breaking the Phalanx. You would end up with about 26 Brigades of between 5,000 and 6,000 men in the active Army and about 11 Enhanced Readiness Brigades in the Reserve.