it is not easy to compare a desktop gpu with laptop gpus, they are completely different and the performance is much lower on laptop gpus.
But that gpu should be very good, and it will probably fit in minimum requirements of any game for now and in future. but of course, some games on lower settings etc...http://www.legitreviews.com/news/12608/
you can see that it is better than the 555m that is a awesome laptop GPU.
but i would say something close to a gts250 for desktop, or something like that. but of course there are other diferentials, new architecture, dx11, etc... but really that is just a suposition;