Shelley's explanation for the closing is in line with Microsoft's: a business decision entirely. "First, they want to divert the headcount tied up in ES [Ensemble Studios] and the costs that are expected to be required to run ES for the next few years into other projects. Second, it sounded like it cost more to run ES on a per person basis than other first party studios (Rare, Lionhead, Forza, Flight Sim) putting us at a disadvantage. ... And third, games those studios are expected to deliver in the next few years are expected to be more strategic and profitable to the company than anything we would be finishing after Halo Wars."

Halo Wars, Ensemble's final game, is now an all-hands-on-deck operation. "In August we shut down work on everything non-Halo Wars related and now the entire studio is focused on finishing this game by the end of this year. Everyone in the studio has a job until Halo Wars is finished." Shelley's statement conflicts with previous reports that employees not essential to Halo Wars have already been laid off.

Shelley also confirmed that a new studio will be founded and primarily staffed by Ensemble alumni. "I believe the spirit and mission of ES will be carried forward in this new company if enough of the key leaders agree to take part, which I expect to happen," he said. Shelley, once the cohort of design luminary Sid Meier, will not be participating in the new studio himself.