According to the game’s official web site, the Manhattan Project Pack is set for a free release next month on Steam.
It has three new maps set in Holland, Italy and North Africa for 2v2 and 3v3 team battles. Two new gameplay modes are also included: Total War set in 1939 with history advancing every 10 minutes with new units and tech unlocked at a fast pace, and Nuclear War which has players building Long Tom cannons with nukes as ammunition.
All sounds rather cool for R.U.S.E. players. Hit up the official site for more.