XNA 4.0 enforces the 512 instruction limit (which the xbox360 has and the HiDef profile enforces as a minumum), whereas XNA3.1 didn't.
If you are looking for an XNA 4 SSAO that has open source, check this link out : Deferred Rendering with SSAO Normals.
I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.