Here are some more details from the IDF regarding the Callistoga, the upcoming 945 Express chipset for the mobile Napa platform. The chip giant also announced Golan, the next-generation Wi-Fi chip, is now known as the ProWireless 3945ABG.
The 945 will feature Intel's GMA 950 graphics core, which it introduced earlier this year in its desktop-oriented 945G integrated chipsets. In its mobile incarnation, the graphics core is clocked to 250MHz, up from the 200MHz at which the 915GM's GMA 900 core is clocked. However, the core can be underclocked to conserve power when it's full rendering strength isn't needed.
Intel VP Mooly Eden confirmed that the GMA 950 will run Windows Vista's composited user interface.
More info about the features of Callistoga can be read at The Register