Microsoft reviving a 'well-loved strategy game franchise' - Halo Wars, Viva Pinata or Age of Empires likely candidates

[sales2099]

"within an established and well-loved strategy game franchise"

I would say Halo Wars, because its community following is pretty niche but dedicated and loyal.

Also, and this is the more logical factor, is that Halo Wars controls were built around a game pad where as Age of Empires would have to be altered and/or have a PC version.