A german site has got there hands on some 81.26 beta forceware drivers which can make use of dual core systems. They show performance improvements of not a lot to up to 50% in one case. Great stuff for all you rich dual core A64 + 7800GTX owners.
http://www.hardwareoc.at/Geforce-7-Treibervergleich.htm
http://www.hardwareoc.at/Geforce-7-Treibervergleich.htm