Right now they have three d-linemen (if you can't Campbell it could be four, more on that later).
They brought in at least six guys last year who all redshirted (I think) who will play O-line, I don't think they're too concerned about it. Especially since Will Campbell appears to have given them a silent commitment, but if it's true we wouldn't know about it until after signing day, hence 'silent.'
I've heard he (Campbell) projects more as an O-tackle than an interior D-lineman, but the nice thing about his versatility is that if they are thin at either line then he will help them there, and he's said he doesn't care which side of the ball he plays.
As far as I know, Newsome is gone for good. He was told by some NFL players that RichRod will not be able to help him get to the NFL, neverminding the fact that RR has done it before with less-touted QB's.
I think Shafer will be here next year. Not sure why, just a feeling. But if he is gone, I hope they go get the Baltimore Ravens D-coordinator (not that it would ever happen, but one can always dream.)