Lift's GUID stuff is a core part of Lift and is not going to change.
It won't change in any respect, ever, no matter what?
It can't. There are so many parts of Lift that depend on the GUID, how the GUD is constructed (including the fact that it's a monotonically increasing value), that trying another scheme will potentially break a lot of code. It would mean a complete re-write of all of SHtml, Screen, Wizard, Comet, and more. Trying to change from GUIDs would mean writing a new web framework.