CBSSports.com's Pete Prisco hands out 2011 NFL Draft Grades for the entire draft. The Steelers get a B-, as Prisco praises first-round pick Cameron Heyward but argues that the Steelers "reached" for second-rounder Marcus Gilbert:
Why did they take Florida's Marcus Gilbert when there were better options at tackle? They reached on that one.
I guess the question would be, who are these better options? Even widening the scope of the question to include any offensive lineman, the really premium players were all gone by the time the Steelers picked Gilbert at the end of the second round. The only offensive linemen who went in the third round were John Moffitt, Will Rackley, Jah Reid and Joseph Barksdale, and none of those guys were widely considered to be second-round talents (although you'd see some of them in second rounds of mock drafts here and there). I suppose it's possible that the Steelers could have waited to pick an offensive lineman, but I'm not really sure there were O-linemen available who were clearly better than Gilbert.
Oh well. Prisco's grades are tough (he only gives three A's, to the Giants, Bucs and Texans, and he does note that the Steelers have earned the benefit of the doubt with a ton of brilliant picks over the years.