As of 10.8.5, Intel's 4th Generation Haswell CPUs and 8-Series chipsets are natively supported in OS X! This means that there is no further need for HaswellHelper or any other installation complications. Systems will work with the standard UniBeast installation method, as long as the USB is prepared using the freshly updated 10.8.5 app.
Apple has also added native drivers for Haswell's Intel HD 4600/5000 integrated graphics. Be sure to use Chimera 2.2 for support via GraphicsEnabler=Yes. We've just posted a refresh to our monthly Buyer's Guide, and we'll be posting details and benchmarks from some of our own test rigs in the coming days. Exciting update!
OS X 10.8.5 Update
Update Your OS X Mountain Lion App to 10.8.5
Building a CustoMac: Buyer's Guide September 2013
The Evolution of Intel's Core i Processors