I'm rewatching the Army AA game right now and keying in on Marcus every play and he's really impressive. His HS highlights don't wow me like I was by Mike Adams', but in this game he is shutting his man down in pass pro. I think he could be the first truly great pass protector at OT we've had under Tressel. He needs to see the field this year, IMO.
Here's a link to the game-
Hulu - U.S. Army All-American Bowl: U.S. Army All-American Bowl 2009
If Browning keeps his starting spot at RT he will have earned it. Shugarts and Hall are no slouches.