Tackling the offensive line is a bit more difficult than other positions, as film is hard to come by, and fewer reviews are to be had.  So this was the hardest of the position reviews to do, but here they are!

G Jon Asamoah:

Illinois - 6'4 and 308lbs, 33" arms.  40 time: 5.07   Bench: Unavailable  Projected 2nd-3rd round

Asamoah is being touted on some reviews as possibly the safest bet in the draft among linemen.  Jon has the pedegree, for sure.  He recorded 80 knockdowns in 2007, while helping Rashard Mendenhall earn a first round draft status, and was a large part of Illinois being first in the Big Ten in offense and second in scoring in 2008.  

Asamoah is noted for good size and strength, quick feet, as smart (was a NFF Scholar Athlete Award winner) and hard working, a good pass blocker and a tenacious run blocker who has experience playing against top talent.  The only knocks against Asamoah have been that he has short arms, in fact the shortest arms of any lineman at the Senior Bowl.

Video

Feature (solid family roots)

Combine Bio

G Mike Johnson:

Alabama - 6'5" and 312 lbs.  40 time: 5.77  Bench: Unavailable  Projected 4th round

Johnson was one of three Crimson Tide linemen to earn All-American honors in 2008 and Johnson followed up by repeating in 2009.  A big strong lineman, Johnson is a mauling run blocker.

Noted strengths include intellect, strength, footwork, run blocking and quickness.  But Johnson is also noted for limited athleticism, and isn't expected to be drafted by a pass first style team, as he is expected to have problems physically with the zone blocking schemes used in the NFL.  His pass blocking is also less than spectacular.

Video

Good Combine interview

G Marshall Newhouse:

Texas Christian University - 6'4" and 319lbs.  40 Time: 4.99  Bench: 25 reps  Projected 4th-5th round

Marshall was instrumental in 2009 to the Horned Frogs scoring offense ranking in the top 10 nationally.  Newhouse has started all but one game for TCU over the past 3 seasons.  He's noted as a versatile linemen who can play both guard and tackle.

His strengths being a solid run blocker with good fundamentals and his quickness but he is knocked for limited strength and has been categorized as a guy who could spend a lot of years in the NFL as a career backup, due to his versatility.

From Yahoo..

C Eric Olsen:

Notre Dame - 6'4" and 306 lbs.  40 Time: 5.25  Bench: 35 reps  Projected 5th round

Eric Olsen has spent time all along Notre Dames line as Charlie Weis tried to use him to fix every problem he saw.  Olsen spent his final year at Center and really excelled there.  Known for being aggressive and just a bit mean, Olsen was a leader and keystone of the Irish offensive line.  He also has a lot of obvious admiration for his dad....

Noted strengths include run blocking, strength (tied for most bench reps by centers at this years combine), fundamentals, versatility and leadership.  The biggest knock against him is that he sometimes gets lost in traffic and can have problems getting to the second level.

Some video

A bit of HS video from Rivals.com

G/T Ciron Black:

LSU - 6'5" and 327lbs.  40 Time: 5.53  Bench: 23 reps   Projected 5th-6th round

Ciron Black has seen his stock free-fall since a poor outing at the combine.  It's kind of unfair, really, and Black could end up being a serious find in the later rounds.  Black is accepting of the idea that, while he was one of the most dominant and durable (Black started a record 53 consecutive games at LSU) left tackles in the NCAA, he doesn't have the quickness or footwork to be a successful tackle at the NFL level.  He has been working at guard, and some team could very well find themselves drafting their starting left or right guard for the next decade as late as the 6th round.

Black possesses elite size, great run blocking skills, and decent strength and pass blocking skills (and he also seems like a really good guy).  But his limited quickness and athleticism are hold him back.

Some HS video from Rivals.com

Prospect video

Some good some bad from Yahoo Sports

Overall, this is a deep class of linemen, and some real gems will fall through the cracks into the later rounds.