The Google Nexus 7 tablet now has a port of CyanogenMod 10 available. Although the new tablet ships with the latest operating system, CM10 brings a number of customisations to the OS.
The CM10 build is also based on Android 4.1 Jelly Bean making the new build simply an enhancement in some areas.
Also, the CM10 build hasn't officially come from Cyanogen. Instead, a user at XDA Developers has compiled a build based on the source code found at CyanogenMod.
To get this working you need to root your Google Nexus 7 and install the ClockworkMod or TWRP recovery and at that point you can then install custom builds of operating systems.
Full instructions can be found over at the XDA Developers forums.