Surprisingly, I think he will actually be good. He already played a quirky cop/detective on CSI: NY. So, it's not a big stretch for him to be FBI, the way it was for Forrest Whitaker in CM: Suspect Behavior.
If they get a good team for him, ones that really do seem like they are FBI, not like that weird team of "charactery" actors they had for Suspect Behavior, who didn't gel with each other, and none of which were Morgan-like eye candy, the show may succeed.