Agree that it seems easiest to just leave Hall down, and Peguero has been inconsistent enough that you could justify (although he wouldn't like it I imagine) sending him down.
I would think Ross is far more likely to be jettisoned than Wilson, who's done solid work both as a starter and reliever.
Hoby has generally been solid and is always available, but with the emergence of Hudson and Koenig (and the aforementioned 40-man crunch coming), I wouldn't be surprised if he's not on the team next year.