If you don't have the slightest bit of optimism in the 49ers considering all the injuries they have dealt with this year, you aren't paying attention.
They still have quite a few holes to fill, but if they can manage to stay healthy next year I expect them to at least improve to a .500 team at a minimum.
Oh, and Fred Warner was calling plays all year. They never trusted Foster to do it because he was essentially too stupid. Go read the stories on it. Saleh and Shanahan tried to spin it as a "oh we just want him to focus on going out and doing what he does best, and that is flying around and playing football".