The Inquirer reports NVIDIA isn't planning to lower their prices until Christmas.
Nvidia doesn’t recognise X1800XT as a competition as it won't ship for another month but it surely is aware of Radeon X1800XL cards as they just arrived in stores. It has GTX and GT cards to compete with it and it's not too worried.
Its new 6800GS will compete with X1600XT and PRO cards that are expected to arrive in middle to late December and Nvidia can ship those cards shortly.
It looks like NVIDIA isn't really worrying about the ATI Radeon X1800XT since it isn't a real GeForce 7800 GTX killer and it won't be available for at least four weeks. In the mean time NVIDIA enjoys the sales of their GeForce 7 line.