Playing in a "keeper league". I have three slots. Who should I hang on to?

Well I would def keep Forte. Jacobs or Jones-drew would be my next one. The rest are ok. I would not hold on to McAllister, he is done, Pennington will be going in the late teen rounds next year so its not worth holding onto. Farve may not even be playing next year so not sure why hold him. So you're left with Welker. That would leave you with two good running backs and a decent wide rec for next year and you could use your first round pick for either a tier 1 QB or Tier 1 WR.