Doing your own projections can be extremely difficult unless you're willing to stray away from pure mathmatics or you're proficient in stats (not the baseball kind, the math course). Possibly the best way to make your own projections is to find a projection system that you trust and make adjustments to that system using your own information. In your case, if you wanted to empasize the 2nd half of 2007, you can favorably adjust those who excelled and negativly adjust those who did not. Most systems haven't been released yet for the 2008 season, but if you're looking to get a head start, MLB Front Office
is currently in the process of releasing theirs.