Character devices ---> Hardware sensors support ---> Section under make menuconfig which was present with prevous gentoo-sources (2.4.22-r7) is now missing. It seems like the i2c patches aren't included in this release as opposed to 2.4.22-r7. Please see http://forums.gentoo.org/viewtopic.php?p=977417#977417
They aren't included. They were problematic to keep in sync with versions of the utils in portage. Emerge i2c and lm-sensors to get hardware sensors support.
Resolving as invalid as the i2c and lm_sensors patches won't be in gentoo-sources anymore.