It's the Nvidia change, not the CPU change that prompted version 2.0.
The following is taken from
http://www.rojakpot.com/default.aspx...var1=26&var2=0
"Do All Revisions Of The NF7-S Motherboards Support The New 400MHz FSB?
Thankfully, ABIT will offer official 400MHz FSB support with all revisions of the ABIT NF7-S motherboard. And why not? After all, the only difference between Revision 1.2 (or older) and Revision 2.0 of the ABIT NF7-S is the use of a new stepping of the NVIDIA nForce2 chipset.
However, a BIOS update will be required for the older revisions to "officially" support the new 400MHz FSB. This is more than just updating the CPU table. Apparently, the new BIOS will feature some tweaks as well. So make sure you get the BIOS updates when they are released if you want to fully support the new 400MHz FSB processors. "