When I talked to Linus Torvalds he said that Secure Boot is a good thing, but can be used in a bad ways. That's proving to be true.
When Microsoft published The Certification Requirements for Windows 8 it was evident that the company wanted to use the secure boot to lock Linux out of such hardware, thus creating a Windows only hardware. The discovery lead to a strong protest from the FLOSS community. Microsoft allowed the non-ARM hardware to be able to run Linux if the hardware vendors chooses to allow that. But as we saw the arrival of ARM on desktop Microsoft "wasted no time in revising its Windows Hardware Certification Requirements to effectively ban most alternative operating systems on ARM-based devices that ship with Windows 8."