Hitting in 2011, Age of Empires Online is an online-only affair with "free-to-play experiences," taking place in a persistent world where your capital city continue to grow even if you're offline. "Social Experiences" including co-op quests and PvP matches will be on offer.

If it sounds a little daunting, the FAQ insists that "Age of Empires Online stays true to its roots with traditional RTS gameplay, a deep player-versus-player mode and detailed historical settings. From the creation of your capital city, to resource management and competitive matches, Age of Empires fans will feel right at home."

Microsoft explains it was inspired to create "a rich social gaming experience" after looking at "how people are playing games today, and the social and connected experiences that people increasingly crave. It's about being able to connect to the entertainment we want, and share it with the people we care about--nearly anywhere."

While Microsoft is playing it coy with pricing--saying only to "Stay tuned for more details"--the mention of "free-to-play experiences," inspiration from social gaming and "add-on content" would suggest that there'll be a basic free-to-play version then paid extras. Such a model has been used in countless social games.

The FAQ also asks itself the probing question of "Why did Microsoft choose Robot to develop Age of Empires Online? Why dissolve Ensemble only to bring back the franchise?" and offers the following answer.

Microsoft Game Studios is always evaluating its business model to determine what is best for both gamers and the company. Many factors were considered in the difficult decision to close Ensemble Studios, but we feel it helped us better align with our goals and long-term development plans. Robot is made up of many of the creative minds behind classic Age of Empires titles, and we're incredibly proud of the work we've done together on Age of Empires Online.

The game's existence was leaked in July, when it was known only as "Spartan" and "Project S." Microsoft's response to the leak is revealed in an e-mail from executive producer Danan Davis to alpha testers, reproduced on a hidden area of the AoE Online site, urging "you're hurting the Alpha process if you leak info about the game."

Age of Empires will be released exclusively for download through Microsoft's Games for Windows - Live platform some time in 2011. You can sign up for beta testing now.