Impact: Recent Moves

Move: Walter Jones and Sean Locklear sitting out
Impact: This move not only gives the backup tackles more work, but it reveals a lot about what the team is thinking. It is now obvious to everyone (although I said as much earlier) that if the two starting tackles were injured the Seahawks would go with Tom Ashworth at LT and slide Ray Willis over to RT, even if he was the starting RG. That tells us that only another interior lineman has a chance to challenge Floyd Womack for a roster spot, who also happens to be returning to the field.
Bottom Line: It is down to Floyd Womack and Pat Ross for the final OL spot

Move: Signed CB DeJuan Groce, Cut P Kyle Stringer
Impact: Dejaun Groce could potentially stick as the 5th CB. The reason behind it would be Jordan Babineaux's health and possible concerns over a lack of experience at the position, with Kelly Jennings and Josh Wilson. However, the impact to the roster would likely be to the defensive line. Keeping a 5th CB would make it hard to keep 10 defensive lineman (the Seahawks kept 10 to start last season, but it was mainly because of guys coming off injuries, and Chris Cooper only lasted two weeks on the roster).
Bottom Line: If Jordan Babineaux isn't ready to go by the start of the year, then Craig Terrill could be out of a job (even though he just returned after being out with an injury).

Move: Signed TE Andy Stokes, Cut CB Gerard Ross, Injuries to tight ends
Impact: The Seahawks now have another body at TE with Leonard Stephens and Will Heller out with "tweaked" ankles and Bennie Joppru just coming back from what were thought to be serious injuries. Heller and Stephens shouldn't be out very long, but that leaves the team with Marcus Pollard, Joe Newton, and Andy Stokes as the only other options for the time being.
Bottom Line: Joe Newton will get plenty of chances to challenge Leonard Stephens for the final tight end spot, but he would need to make remarkable progress very quickly. Andy Stokes will be cut as soon as the others are healthy enough to fully participate.

Clarification: For those too lazy to read the comments, it appears that either Bennie Joppru's injuries are less serious than Mike Holmgren initially thought or I misinterpreted his vague and somewhat misleading comments in response to a question about the injuries sustained in the scrimmage and how long the players were expected to be out:

"Actually the fellas that were nicked up in the scrimmage – they came out better than we thought at the time," Holmgren said. "Ben is OK. The most serious injury, I guess is Joppru. He had a real painful hip pointer and he also pulled a muscle when he hurt his leg. Courtney has a knee injury and it would keep him out probably four weeks."

In either case, Mike Kahn at Seahawks.com reported on August 16th (just 11 days after Holmgren made those comments):

Joppru was out there for the afternoon practice on Wednesday (August 15th), and did some of the drills. Thursday morning he participated in full pads and he moved very well. He had hip-pointer and muscle strain that were very painful to start with – and the therapy provided by trainer Sam Ramsden and his staff has helped him heal rapidly. I noticed on Tuesday that Joppru was moving around pretty well.

They didn’t want to rush him, but they needed him back to take a good long look at him to see if he can help. He’s one of those guys – a second round draft choice from Michigan – who has never bee able to stay healthy long enough to prove whether he belongs in the NFL or not.

Frank Hughes at Seahawks Insider also reported that Bennie Joppru was "back in full pads and participating in full-contact drills."

And as noted in the comments, if Joppru can get out there and compete for a job, then things change considerably, although I would still give the upper hand to Leonard Stephens if he gets back on the field anytime soon. It is also worth noting that if Joppru's injuries really aren't a concern anymore, then Andy Stokes might find himself off the roster when either Heller or Stephens is able to fully participate in practice. It also remains to be seen if Joppru just knows that his only chance is to get out there and play through the pain.