Comment 8 for bug 262309

Artemis, I agree with your points; the long term solution is probably in GRUB 2's scripting support, but we're stuck with GRUB 1 and update-grub for a long while still. :-/

uuid is to set the command to set the root device from an UUID; I think the plan is to move to the "root" command and pass an UUID as argument (which I think is supported in Debian's GRUB 1 or GRUB 2, not sure); the uuid command is an Ubuntu-ism and isn't supported in Debian at this point.

The quiet command is also an Ubuntu specific patch; it's used to disable some of GRUB's output. Having worked a little on this myself, I need to say GRUB's boot progress messages are a bit chatty when you try to achieve a clean boot experience (think OSX). This patch is probably going to stay for a while.
  There's something weird though, quiet_boot seems to be the default; I suspect we could drop the actual command calls and use quiet 0 / quiet 1 command instead of the current useless "quiet" in menu.lst. You're welcome to file bugs / patches on this topic if you like, I think we could much improve this option and general chatiness of grub during initial boot.

You can find some bits of documentation on the automagic feature in the update-grub(8) man page.