Ok, since a little time has passed since I posted the original article and question, I'll offer up a few words here.
Is Donovan McNabb receiving extra scrutiny compared to other quarterbacks? Yes. But not for the reason that he think's he is (certainly not because of race).
He receives extra scrutiny and extra criticism because he plays for the Philadelphia Eagles, a team with fans that are notorious for hating their own team's players no matter how good they are. If you haven't brought 'them' a championship in the last 2 seasons, then you must SUCK in their mind no matter if you could otherwise walk on water.
As some Sports talk radio guys in the D.C. area posited today 'can you imagine how beloved Donovan McNabb would be in D.C.?' -- yes, yes I can. He'd be nearly a god in D.C. He'd be revered and worshiped. He'd still get criticized for how he plays if he screws up, but he'd get a lot more forgiveness and see a lot more patience for his play if he played in D.C.
The time when being Black was really a distinguishing factor for Quarterbacks passed some time ago, despite the comments made by Rush Limbaugh a few seasons back when he had his short employment with ESPN.
That barrier has been broken not just by Doug Williams, but by Warren Moon, Randall Cunningham, Vince Young, Michael Vick (though Vick broke a lot of other things that shouldn't have been broken along the way
), Jason Campbell, and others (see list up above that I didn't mean to copy but was thinking about in a similar fashion while speaking up here).
McNabb takes a lot of heat because his team hasn't gotten over the hump. They got to the playoffs, made it to the superbowl, but were soundly defeated in that superbowl. Not necessarily because of McNabb, but then again as Terrell Owen's would tell you HE MOST CERTAINLY WASN'T THE PROBLEM

Personally I'm tired of RACE being used as a factor in just about anything in this country. I wish we'd get well past that being the case. But, for as long as people *can* bring it up as a consideration, it may never go away.