According to the Seahawks' official Twitter feed, G Deuce Lutui, MLB Barrett Ruud, and CB Roy Lewis have all agreed to terms with the team.
Of the three, Roy Lewis is the most likely to still be on the roster when the regular season rolls around. Lewis is an above-average special teamer, but he's also proven to be an asset as an extra DB in various defensive packages. His coverage skills have steadily improved since he joined the team in 2009, and he also has some value as a blitzer.
Barrett Ruud made a bit of a name for himself as a tackling machine for the Buccaneers, but groin and shoulder injuries hobbled him last year in Tennessee, where he appeared in just nine games for the Titans before being placed on injured reserve. Ruud has great coverage skills, but is notoriously bad against the run. Unless he can suddenly figure out something about tackling running backs that he failed to pick up in his first seven years in the NFL, his best chance to make the team will be on special teams.
Deuce Lutui should be a familiar name, since he's played against Seattle twice a year as a member of the Cardinals ever since they drafted him back in 2006. He lost his starting job last season after reporting to camp overweight for the second year in a row, but prior to that he started 72 games at right guard for Arizona. Lutui has plenty of talent -- when he shows up to play, he can bulldoze run lanes open with the best of them -- but it's unclear whether or not he still has the drive to play at a high level. If Tom Cable can motivate him, the Seahawks will have gained a starting-caliber lineman; if not, expect him to be shown the door in a hurry.