While I didn't really like Halo 3, I did really enjoy Halo Wars. Yes it is simplified, but Ensemble have done a great job making it still feeling satisfying, but great to control. Oh, and amazing CG! I have never played online multiplayer in an RTS, but I have taken advantage of my month of gold for £1, and have really really enjoyed it.
Anyway, we all know that they have been closed, so will any other studio take up the mantle, or will one of the studios formed in the result (Robot Entertainment, Bonfire Studios and a few more). The game sold fine, so it was likely a profitable venture so surely Microsoft would want to keep the "franchise" going and expand Halo further