Nordichardware managed to get news about the upcoming dual GPU from nVidia, which will be calld GTX 590.
NVIDIAs upcoming flagship graphics card is going to be launched in February to fight AMD with their Dual-GPU card, the Radeon HD 6990. With no less than two GF110 onboard, or in other words 1'024 Cuda Cores, it's going to have twice the performance of a GTX 580 - theoretically - but as the power consumption of the 580 is huge, they are going to launch the GTX 590 with less voltage and less frequency on the core.
Source: NordicHardware