I finally have 0 compile errors and the game playable again thanks to a lot of the blogs out there that have already gone through this ordeal. I found Shawn Hargreaves Blog to be extremely helpful. Not only does he go through most of the changes from XNA 3.1 to 4.0, but he also explains why those changes were made. It really helped me fix the numerous compile errors I was getting. He sums up why so many changes were made with a simple quote from Banjobeni, “If you break it, break it good”. Another link I found helpful was Nelxon’s XNA 3.1 to XNA 4.0 Chear Sheet. For everything else, Google and MSDN.
I haven’t emerged completely unscathed though. I did have to rewrite major parts of my Save-Load system as well as parts of my custom vertices and FX files. My particle explosions are currently broken because PointLists are no longer supported and I currently have several objects that aren’t correctly rendering. It will probably take another day’s worth of work to get it all sorted out.