Just days ago, Nvidia announced its new GTX 980 and GTX 970 graphics cards along with the GeForce 344.11 driver. Very shortly thereafter, Nvidia launched the 344.16 Beta driver, which has now been WHQL certified and is available for download.
It's not exactly clear what the new drivers have to offer, as there is no mention of any performance improvements or new profiles. The only update that we can spot (beyond what the 344.11 driver offers) is that the Code 49 and Code 43 errors have been fixed for when using one of the new cards on an Asus Rampage Black or ASRock X79 series motherboard.
WHQL (Windows Hardware Quality Labs) testing is a process designed by Microsoft that ensures drivers don't present any issues when being used with various third-party hardware and software packages. A WHQL-certified driver therefore assures you a certain level of stability and predictability in most use cases.
So, in short, if you have compatibility issues with the new graphics cards, download and install this driver. If you aren't having any issues, you're probably better off saving 200 MB of your Internet bandwidth cap, if you have one.
You can download the driver here.