It is said to utilize the same PCB as the GeForce GTX 470, but featuring 1GB of GDDR5 memory connected via a 256-bit bus and presumably cuts specs across the board. By comparison, the GTX 470 has 1,280MB of GDDR5 RAM and a 320-bit memory interface. Interestingly, Expreview claims there will be no formal reference design for the GTX 460, with each partner free to make a slightly different version.
Previous rumors suggest that other cheaper Fermi derivatives based on new silicon could arrive around June as well. These include a GeForce GTS 450, 440, and 430 -- all of them based on the 40nm GF104 core and priced under $200.