There are two things I've not heard from Red Hat on this issue: 1) The (in)validity of the approach in terms of addressing the problem/need for secure OS boot.

There are two things I've not heard from Red Hat on this issue: 1) The (in)validity of the approach in terms of addressing the problem/need for secure OS boot. 2) An alternative approach for achieving the same result. The practicality of the situation is this: in evaluating a trade-off between running Win8 securely on a PC/device vs. being able to install another OS on said device, the significant majority of users are going to forego the other-OS-install capability.