Speaking at a Microsoft press event last week, Ensemble designer Graeme Devine stated definitely that there won’t be a Halo Wars for Windows despite rampant speculation that the Halo-themed RTS would end up on PC.
While he does state it, Devine also noted that the final decision rests on Microsoft: "Zero. Never. I’m going to go on the record and say never ever! Microsoft may go and announce it, but I’ll say never."
As for Ensemble’s successor, Devine commented that an announcement is coming soon and that a “new studio [is] forming that will rise from Ensemble.”
The E3 2007 Halo Wars presentation has finally been released. This 10-minute video offers gameplay footage with narration by lead designer Graeme Devine.