As I look at the latest mock drafts, here's an example from CBS Sports, I usually see all the top offensive tackles gone by the time the Green Bay Packers select at No. 32 overall. Rob Rang expects five offensive lineman to be drafted in the first round. The final one, Mississippi State OT Derek Sherrod, he projects will be selected by the Steelers one spot ahead at No. 31.
But if it's like 2010 all over, maybe one of those lineman could fall to the Packers spot. RT Bryan Bulaga was projected as high as No. 6 to the Chiefs at one point. But in the end, he slid all the way down to them at No. 23.
As far as the top five lineman go, here's a good rundown by Bucky Brooks at NFL.com. Colorado's Nate Solder is currently projected where Bulaga was in 2010. But he appears to be the best offensive lineman available, so he should not fall out of the top half of the first round. Bulaga was far from the first lineman drafted and he dropped, in part, because other lineman were rising.
Boston College's Anthony Castonzo and Mississippi State's Derek Sherrod are similar players, athletic with good lateral quickness, and Castonzo's rated higher because he appears to be more of a finished product. Wisconsin's Gabe Carimi is the mauler of the group and is projected as a future right tackle (which might be just fine for the Packers). I don't expect the Packers to have any interest in USC's Tyron Smith because he played well under 300 lbs. during college (though I've heard he's now up over that for the combine).