O MacRumors found references to possible updates of iMacs and Macs mini in a configuration file present in the version of Mac OS X that comes standard on the new MacBook (+ Pro). Some lines of code present in it mention a Mac mini model 3.1 (the most recent 2.1) and a iMac 9.1 (the most recent 8.1):
The indication ?CFG_MCP79? that appears in the first tagstring of each of the two items highlighted in the image above refers to the MCP79 graphics chipset, used by NVIDIA in its most recent GPUs.
This indicates that both the new iMac and the new Mac mini will exclusively use NVIDIA graphics, eliminating the use of Intel integrated graphics on new Macs and limiting ATI graphics as an option for the Mac Pro – if that's your next. update does not eliminate them, too.
If you own a MacBook or MacBook Pro released in October, you can check the code from the image above in an Info.plist file in / Library / IOPlatformPluginFamily.kext / Contents / PlugIns / ACPI_SMC_PlatformPlugin.kext / Contents /.