Oh, don't worry: more options have been removed again: setting browser.urlbar.update1 = false no longer gives you back the old, unintrusive urlbar behavior. Mozilla UX people have once again shown that they know best and you won't need to worry about getting a bad user experience just because you mistakenly thought you liked it.

Edit: Changed 'disabled' to 'removed' in the first sentence, as it's probably clearer.