There seems to be a lot of misconceptions about secure boot. It's not really a "back door," it only prevents the bios from booting operating systems without a specific uefi key that was packaged with Windows.

A few months ago, Microsoft gave a couple developers some debugging software, and accidentally the "golden key" was packaged with that software. That is, the secure boot key that their Windows operating system uses. Since then, the developers have notified Microsoft of their mistake, and have recently released the key to the public.

What that means for you, is that now non-Windows operating systems (namely linux and a couple others) will soon be able to run on secure boot systems that have been locked down to only accept the Microsoft secure boot key. This only has huge significance on a handful of machines, as most devices allow the user to add secure boot keys or turn off secure boot. It'll also make it easier to install linux on machines that are running secure boot, as they will have no problem booting an OS that has Microsoft's secure boot key without extra configuration in the bios.