Andrew Morton has integrated the new nForce/nForce2 GPL ethernet driver into his 2.6.0-test9-mm2 patchset, for anyone who wishes to try it out.
You can get it from here:
To apply the patch to a standard 2.6.0-test9 source tree, cd into the root of the tree, run the make clean command, then run this command:
zcat /path/to/patchset/2.6.0-test9-mm2.gz | patch -p1
Then run make xconfig and go configure the driver under the Networking -> Network devices -> 10/100 Ethernet menu.