Surprised? You shouldn't be, considering NVIDIA drivers caused most of the crashes in Windows XP as well. It's just Vista's more graceful when it comes to handling said failures.
When Vista and DirectX 10 were announced all those years ago, it wasn't the graphics that had my giblets tingling. No, it was integration. Vista promised to treat your graphics card as part of the normal make-up of a PC, rather than an optional extra, by delivering GPU multi-tasking/scheduling and virtualised video memory. With these improvements, we got Aero Glass, Direct3D 10 and, of course, the Windows Display Driver Model (WDDM).Put simply (and I mean simply), Windows XP loads video drivers in kernel mode, which provides better performance to the detriment of stability, while Vista loads them in user mode, which has the opposite effect. Even Microsoft's own article on WDDM lists stability first under the driver model's benefits.
The point of switching kernel mode with user mode wasn't to reduce the number of video driver-related errors - it was to stop them from bringing the whole system down. Which, in my experience with the OS, it's done a decent job of doing.
But yeah - unsurprising numbers are unsurprising. What is amazing is that NVIDIA still hasn't done much to fix these issues. At least with AMD's cards you can reboot the GPU when it fails.
Vista-Capable Lawsuit Paints Picture of Buggy NVIDIA Drivers [Ars Technica, via Gizmodo AU]