Maybe easier to list what hasn't change...
Here is a partial list...
* support for AMD64/X64/X86-64/whatever you like to call it... (obviously...)
* no support for Windows 9X in POIDE, and probably most tools except POLINK & POLIB...
* support for C99 complex math...
* support for "safer" C runtime functions from ISO TR24731-1...
* basic "locale" support...
* some 30 -40 new compiler intrinsic functions...
* Windows Vista support...