I tried this out with a number of games, kinda underwhelming. It does work pretty well with M&B though, the other characters and especially the foliage on the ground looks pretty 3d.
My problem is with my character, the colors are not blending for my guy, its red/blue bleed through, especially on my sword as it comes towards the screen, horrible separation of the colors (like changing the depth too high but its still 15% default). Everything else looks good but my character has so much bleedthrough on the colors that my eyes don't see it as 3d, its just ugly. Lowering the depth might work but 15% is already very low, the 3d effect is not very pronounced with that setting so going lower ruins the whole effect, if anything I want to raise it.
Also yes it (supposedly) works with every game as, like you said, its a driver enabled feature. Some games have issues with it, some games have almost no 3d effect using it. I tried it on GRID and the game was slowed to a crawl until I disabled shadows and motion blur (The nvidia overlay tells you to do this when playing for the 3d to work), but once I got in game it was barely any different then 2d. Tried it with L4D and L4D2 as well, L4D2 crashed when I loaded the main menu, but L4D worked fine (Both are supported in nvidia's 3d game list), once again the 3d looked pretty crappy, and just strained my eyes more then anything. M&B seems to work the best so far, I guess its because of the much brighter lighting and more emphasis on characters then environment shading and such.