It seems that a slower version of the current GTX 460 is in the works, a slide presented by Heise.de shows a cut down version of the card with 288 Shader processors. The interesting part is that the card does come with a full GB of graphics memory which uses one more memory controller, and thus accumulated to 256-bit memory (opposed to 192-bit).
The card's clocks will be fairly similar, 20 MHz slower at 650 MHz and the memory 50 (x4) MHz slower wich is effectively 3.4 GBPs.
The card has the same TDP at 150W and will be introduced on the 15th of November. Slide is courtesy of heise.de
