Next years team will be well built around whoever our next starting QB is. The o line will have more experience and return our best player. Running back will have fresh faces but is loaded with potential.
What I would project of offense
T: Dietrich
G: Todd
C: Luke
G: Weyer
T: Schmaing
WR: Henderson / Burke
WR: Jones / Rogers
WR: Naccarato / Jannssen
TE: Ralston
RB: Nguyen / Favors / Logwood / Counts
QB: Gustafson or Simis
Honestly, that's a pretty damn good offense on paper. You've got great skill players to help the new QB along and a stable of running backs again. Also look at the o line, it would be back to the size and strength we're used to seeing. That group would average about 20-25 pounds heavier than this years O line.
On defense there's a few more gaps though;
DE: Crittenden
DT: Kidder
DT: Peevey
DE: Holmes
OLB: Gamboa
MLB: Kose
OLB: Van Ackeren
CB: Nelson
S: Whitted
S: Dallassera or Johnson
CB: Harris
A few more gaps on defense, replacing Wags and Takai will be tough but fortunately it's with guys that have played a ton this season. Dennard graduates and Nelson will step in nicely. Safety where Hermey leaves is a bit of an unknown, roll over Dallassera or elevate special teams stand out Johnson?
Overall, again, there's key losses but a lot of core players return, including the full 2-deep of LBs and really only safety would be the spot where you may break in a player with very limited prior on-field experience.
Honestly I don't see much reason to suggest that 2015 will be a rebuilding year at all.