Since I believe the gaming industry will eventually recycle video games like Hollywood does movies, I'm of the opinion that we will eventually see a Bully 2 & Manhunt 3 sometime in the far, far, far distant future.
By that time, Jimmy will be 50 years old and will be a permanent resident at the rehab place in New Coventry, sneaking over to the school to bully the 'new kids' for kicks and leech at the young girls. Cash will come back out of his retirement as an assassin to take on a new set of challenges, helped along with some pick-me-up drugs from his friend, Doctor Danny.
Until then, we can only wait....and hope.