64 Bit Changes for the CLR

JIT compile IL to native 64 bit instructions, will be optimized to specific processor type.
Sizeof(Pointer) <> Sizeof(Integer)
IntPtr type 64 bits wide
P/Invoke only works into unmanaged Win64 code.
Delphi note:
Delphi 8 with Winform's work fine with no changes.
Delphi with VCL will need some changes. Specifically because THandle is declared as Cardinal (32bit) in many places and it's size changes. So this needs to be addressed before the VCL will work on 64bit.