This may have been mentioned in the thread already...but if you have an SCCM 2007 environment the built in USB 3 drivers in Windows 8 prevent the machine from completing a hardware inventory. The driver contains a null character at the end of the driver name and it causes the inventory process to stop. You can go through the steps to load the Windows 7 driver and it fixes it...but this shouldn't be necessary.
I will state that the problem isn't limited to just Intel's USB 3.0 controller driver. We have machines with Renasas controllers that have the same problem.
Fortunately, I only have a handful of Windows 8 machines deployed. I don't yet know if this problem exists with SCCM 2012. We're in the process of migrating to that environment now, but I'm not at a point where I can transition my clients over to it, yet.
EDIT: Turns out Microsoft released an update that's supposed to fix the problem: