It is said that NVIDIA will launch its NV43 at the upcoming game convention in Leipzig, Germany from the 19th till 2nd of August. The NV43 is a mainstream 110nm card with eight pipelines, 256 bit memory interface, a 425MHz core and 450MHz memory.
This core is much cheaper to produce than NV40 generation as its die is smaller. A 110 nanometer will still remain more expensive then 130 nanos but this will level up or get cheaper soon. You just have to build up the volumes.
As for shader support, Nvidia is dedicated to go for Shader model 3.0 only with its new chip and put some additional pressure on ATI non Shader model 3.0 company. But eventually ATI Shader model 2.0b will work just fine, you will see when you see the first scores.
Those NV 43 cards are expected in autumn but you never know when they are actually going to be available.
Nvidia has the chance to ship these cards before ATI's RV410, according to the latest forecasts. However, launching it in late August doesn't mean that you will be able to actually buy it then. Let's go and hunt down its name now.