For two days this week, Nvidia has released new versions of their ForceWare driver packages. They released the new 169.21 series for Windows XP on Wednesday, and yesterday they released the 169.25 series for Windows Vista, both 32-bit and 64-bit varieties. It's a bit interesting that they just happened to release their new drivers the same day that ATI makes a new Catalyst package available.
These are the same drivers that were available as non-WHQL, so they aren't bringing any new features to the table. They do have 3-way SLI support and support for all the current GeForce cards including the newer 8800 GTS series.
They also have made a new driver package for Linux available for download. Unlike the Windows package this one adds quite a bit of new features. Rendering bugs of various sorts have been fixed, modesetting on the newest GeForce cards has been added, stability fixes and much more has been included. It's quite a laundry list of updates, but we've come to expect that from Nvidia - they have done extremely well in the Linux driver department.