VideoCards reports NVIDIA has introduced new low-end GeForce 600 series graphics cards for OEMs. Some of these models are rebrands of Fermi, while others are new parts.
It looks like GeForce GT 630, and two variants GT 640 128-bit are brand new Kepler graphics cards. GeForce GT 645 is a refreshed GeForce GTX 560 SE. I’m not sure at the moment which GPUs are those cards using (NVIDIA didn’t provide such information).