Meh, I can list some major Nvidia screwups, too. (Grotesque GeforceFX era optimizations, anyone? Or even todays texture shimmering at default settings...)
But the fact is for video editing, it doesn't matter. Ati drivers are great, and so are Nvidias.
In fact, if you're into video rendering and encoding, Ati's AVIVO drivers will give you a huge speed boost in some circumstances. Purevideo doesn't yet use the GPU to accelerate encoding, from what I understand.