Stocking up on the big men is always a good thing.  The wear and tear on these guys is outrageous and it never hurts to have a collection of 300 pounders around.  A work in progress, he won't grab a starting role right off the bat, but can be developed and will provide rotation for starters.  From Reiss's Pieces:

Ohrnberger, a player who took a pre-draft visit to Gillette Stadium, adds youth to the interior of the offensive line and provides a fallback, longer-term option with starting guards Logan Mankins (left) and Stephen Neal (right) entering the final year of their contracts.

The Patriots’ top backups at center/guard – Russ Hochstein and Billy Yates – also have contracts expiring after the 2009 season.

draftcountdown.com says:

A three-year starter for the Nittany Lions...Has experience on both the right and left sides...Was named 2nd Team All-Big Ten as a junior and 1st Team as a senior...Could project to either guard or center at the pro level...Best fit will most likely come in a zone blocking scheme.
 

 Again, a work in progress, but it's good to have another young guy in the pig pile.