In my opinion:
Foster - This looks like a no brainer to me. Word is he will start, and the panthers are switching to a zone blocking scheme which suits his run style better.
Jones - From what I hear Jones is going to be the "primary runner" this year, and he was pretty good stats wise when he started in that role, so I think he will have a good season.
Betts - Guy is a good talent and I just don't trust Portis' knee. I think Betts will see a lot of playing time.
Barber - I think he will only be good for TDs this season. Of course that is where a lot of fantasy points usually come from, but still I think he will have a diminished role in the O this year. He might get close to the same fantasy points total as Betts, but I think Betts will have better opportunities to be on the field.
Jordan - Just don't trust this dude after last year. Back problems, poor running, bad attitude, he even said something about retiering last year? (not sure about that, but he did have some wishy-washy attitude when his back got injured) I could see giving him a second chance, but I just see the raiders backfield as a work in progress. I think they could plug in Fargas, or Rhodes, or Joe at any given moment and poof! Jordan looses out. I just ask myself if he is a better back than anyone else on that team and the answer I get is "I don't know".