The motherboard Rev. is nothing more than that. Just a revision of the motherboard. Its not a clear indicator of what components are to be attached. These motherboards where developed by Toshiba and are used in many other applications outside the TypeX2.
Also, the Core2 setups where mostly for the shitty touchscreen games, and I think one version of SFIV. Its really not needed though as these games where well optomized. USFIV officially runs on the P4 with 1GB of RAM and a 979GS. Thats what the newest Nesica TypeX2 motherboards are using.
Not that I found the 7900GS lacking, but I upgraded to the 7950GT with 512MB of ram and saw ZERO performance improvements. Im really impressed by how perfect these games run on such low end hardware.
On a side note, I do not believe the northbridge supports more than 2GB of RAM. I could be completely wrong on that though.