The news that&nbsp;former Xbox chief Don Mattrick was&nbsp;leaving Microsoft to help revive the social gaming company Zynga&nbsp;has people wondering&nbsp;if&nbsp;Steven Spielberg will stick with Microsoft&rsquo;s planned&nbsp;TV series based on the video game&nbsp;Halo.
The&nbsp;Halo&nbsp;series will, of course, proceed without Mattrick, but given that Mattrick&rsquo;s close relationship