That is, the bindings should not be attached using css. Instead a table for some other structure to map tags to bindings. Variations of the type attribute can also be used, and as a special case, the textbox multiline attribute and the menulist editable attribute, or those could be deprecated in favour of using the type attribute. This would allow bindings to apply immediately and never be removed.

Hmmmm... How will this impact third-party apps extensively relying on XBL to extend the XUL widget set and sometimes selecting elements with rather complex selectors to attach bindings? That's the case of BlueGriffon FWIW.

It would work the same. I wasn't suggesting removing the -moz-binding property. In fact, it would work better since you wouldn't need to extend an existing toolkit binding.

Web Components \o/