Microsoft Studios is still active, however, Ensemble Studios who developed Age of Empires was closed in 2009. Then you have Skybox Labs who built "HD" versions

Microsoft Studios is still active, however, Ensemble Studios who developed Age of Empires was closed in 2009. Then you have Skybox Labs who built "HD" versions of some of their games. Some guys from Ensemble has since formed Robot Entertainment, released e.g. AoE Online, and is supposedly (?) using Microsoft as publisher once again but I don't think they're part of Microsoft Studios anymore. AoE Online was shut down in 2014 though. :/