As reveleaed over the weekend, Sierra Entertainment and Mad Doc Software today officially announced that they are working on an Empire Earth 2 expansion, it will be titled 'The Art of Supremacy' and should be available next spring. New features are listed below.

• Two new modes, including Fealty Mode, where players on the ropes can declare "fealty," to become a permanent ally or vassal to another player; and Tug-of-War Mode, where multiple battles are fought across three, five, or seven maps with ultimate victory coming from defeating a foe on their home map
• Three new globe-spanning campaigns will allow gamers to relive more of mankind's most legendary moments, from the time of the Pharaohs to the reign of Napoleon
• Ten new combat units, including Zulu Warriors, Russian Howitzers, and Rafale Stealth fighters, with which to conquer the world's most powerful foes
• Upgrades from regular units to powerful Heroes in victory
• The ability to conquer, assimilate or ally with Native Tribes
• New persistent units that will remain and retain upgrades across multiple scenarios
• New strategies to master in new game modes, with advanced units and additional civilizations
• A new editor that allows the player to create unique custom civilizations
• A streamlined and improved multiplayer matchmaking interface

There's also a bunch of Empire Earth 2: The Art of Supremacy screenshots in our gallery