Here's some information about the changes made:
According to the P897 design plan that NVIDIA sends its partners, it uses 4/6 phase NVVDD power solution ADP4100. It changes FBVDDQ power solution from 2-phase to single phase. And the MOSFET package has been changed from LFPAK to DPAK to save cost. Another noticeable change is the PCB layer decreases from 10 to 8. The length of PCB keeps unchanged, while the height of it is reduced by 1.5cm. In order to cut cost further, they will change DVI connector, crystal and probably change BIOS Rom from 1M to 512K.
While there's undoubtedly going to be people who refuse to purchase a GTX 260 using this cut-down PCB, the average joe won't notice the difference and with the PCB said to reduce the overall manufacturing cost on each card by up to $15 USD, one would expect the shelf price of these cards to reflect that somewhat as well.
According to Expreview, GTX 260s using this new PCB are expected to reach partners by the third week of this month.