We live under the threat of UEFI and Microsoft for some time, even if we understand the necessity of a secure boot, but things are starting to be put in motion.
Canonical is a Contributor Member of the UEFI Forum and is trying to be actively participating into the UEFI specification process, aiming to preserve users’ ability to install whatever operating system they desire.
The negotiations are not complete and it's unsure how UEFI will affect the relationship between Canonical and its OEM partners, but Ubuntu 12.10
will have a revised bootloader in order to ensure an “it just works” experience.
Moreover, GRUB2, a Canonical project that has a lot of development behind it, will not be used on UEFI-enabled systems because it would create legal problems due to its GPLv3 license.
“In the event that a manufacturer makes a mistake and delivers a locked-down system with a GRUB 2 image signed by the Ubuntu key, we have not been able to find legal guidance that we wouldn't then be required by the terms of the GPLv3 to disclose our private key in order that users can install a modified boot loader,
” said Steve Langasek, a developer for Canonical.
More technical details about this problem and about the future of Ubuntu can be found in the official mailing list