I played around a bit with the Digital Vibrance control on my Nvidia card to see what you were talking about. I normally have it set to 0 since I use a monitor calibrator/profiler.
It looks to me like it is mainly boosting saturation. The Nvidia tech papers try to imply it is doing other fantastic things beyond that but I don't really see it. It may be boosting warm colors slightly more than cool ones but since the adjustment affects the display directly it is isn't possible to do a side by side comparison without taking a photograph of the display or using two equal displays side-by-side.
If you shoot raw and use camera raw with PS, I think boosting the saturation slider and maybe adding some clarity should take you in the right direction.
If you are using PS alone, just try boosting saturation. To simulate Clarity, use Unsharp Mask with a high radius and low amount. That often works well to remove minor haze.
Some other techniques that you might want to play with:
- Create a duplicate layer, apply a subtle Gausian Blur, and put the duplicate layer in Soft Light mode.
- Edit>Convert to Profile (LAB). Bring up Curves and for the A and B channels, move the upper-right endpoint to the left and the lower-left endpoint to the right by the same amounts. Convert back to colorspace of your choice.