I honestly don't know which ones--if any--would be lost in the upgrade. I use several that seem to update themselves fairly quickly with each firefox update.
Each time I upgrade with Firefox, I lose extensions, some of which I use daily here on FR and other BB's (Word count plus, Tab X, BBCode and BBCodextra are just a few). However, there are two extensions you can use to test compatibility and one also forces use if they still work:
Of course, the purpose of add-ons is to make your browsing easier. When new versions of the browser seemingly come with the speed of light leaving functioning add-ons behind, then users are going to search for another browser to use which mitigates the whole purpose of add-ons in the first place!