Just saw on ESPN First Take that Mike Martz has been fired. I came in late on the report they were giving, but it sounded like they said offensive line coach Jim Colletto has been hired as his replacement. Before you take that to be 100%, realize that it is ESPN, who has been notorious for providing incorrect news lately, especially with Michigan teams.
I'll try to find some confirmation on both the news that Martz is fired and who his replacement is and will update this story when I do.
Update [2008-1-2 12:12:41 by Sean Yuille]: It appears that Colletto and Kippy Brown will share the duties of OC. I'll have more in another post.