Firefox 4 will be released today. As with every major version update, this one is still suffering from the same issue: add-on developer haven’t pushed their add-ons forward to work with the most recent version of the web browser.
Although most of them might still work, a few of them, e.g., the inline PDF display add-on on the Mac, will break. Best case, the add-on will be marked as incompatible but the user can still use it (if they disable the compatibility check). Worst case, a feature which the user got used to is suddenly gone (“It used to work! Why is it broken after the update?”). And they’re not going to blame the add-on author, they’ll rant against the Firefox browser or the folks at Mozilla.
I hope Mozilla can come up with a plan to encourage at least the authors of the most downloaded/used add-ons to fix their add-ons as soon as possible – prior to a major release.
Update: The AusweisApp add-on (used for authenticating yourself on a number of websites using your German ID) is just one of the add-ons which broke after the Firefox 4 upgrade…