Any break from the XUL days are a huge plus. XUL gives you so much power but is very unsafe for the users since anything goes and that system is also very poorl

Any break from the XUL days are a huge plus. XUL gives you so much power but is very unsafe for the users since anything goes and that system is also very poorly documented. I sometimes had to look at the Mozilla source code to understand what was possible with the XUL based extension system. Now that we have a really great set of native dev tools inside Firefox maybe we don't need XUL anymore? I say that because maybe something like Firebug isn't possible without XUL.