Summary: It does work on linux and windows with dual 2560x1600 displays while only consuming 35w but it is slow and vmware has issues with it when switching from guest to host and unity. Probably not enough memory for this setup. Upgraded to the newer 510nvs and it is significantly faster and works very well. Get the new one!
Summary: I'm using Kubuntu 13.10. The card's low memory per GPU is less than satisfactory for a KDE desktop on two 2560x1440 displays on one GPU, with compositing turned on. It works ok when compositing is turned off (either with both displays on one GPU or when using both GPUs). I guess I was expecting something else at this price point.