It looks like Expreview seem to have heard that Nvidia is all set to release the GTX 590 on March 22nd.
AMD just rolled out their dual-GPU HD 6990 monster, taking the performance edge from Nvidia albeit for a while. But it seems Nvidia is almost ready to announce to the world their counter-attack on AMD.
The GTX 590 is a dual graphics card based on the GF110 core, sporting 1024 CUDA cores and 3 GB of GDDR5 graphics memory.