Some partners have canceled their Geforce GTX 260 orders months ago, but some of them are still trying to sell them. The demand for any kind of performance cards is huge, as ATI cannot deliver enough of its 58x0 cards and Nvidia is definitely having only a hand full of GTX 260s available for sale.
From what we hear, the demand is about 10 to 1, or around that number as Nvidia ships some 1000 chips in case you order 10,000. This depends from partner to partner but every one of them has GTX 260 cards on allocation.