Version-less updates of browsers makes sense, and they should be seamlessly, silently, updated in the back-ground. This is getting crazy.
I install Firefox for friends and family who I want off IE, and this actually embarrasses me a little. If I have to keep telling them to update, they will quit - or end up using REALLY OLD versions of Firefox and we'll have an IE6 situation all over again soon but with Firefox.
I'm starting to install Chrome now. At least I can say that their browser will always update, and they have nothing to worry about.
The upgrade to 5 isn't much different than going from 3.8 to 3.16. Mainly, they've changed their numbering scheme, so there's no reason to make a big deal about it.
Here's the about Firefox dialog http://i.imgur.com/cDbN1.png and the update request http://i.imgur.com/4SYRI.png
That's not to say I don't see the allure of automatic updates, but I just don't want them to be silent and mandatory.
EDIT: also, the bash script is there because I install Firefox to /usr/local, and it's easier to type "update-firefox" in an already-open terminal than to reboot Firefox as root so it can modify my files. I'm aware it's redundant, but it also a) requires my active participation, so I can't miss it and b) lets me downgrade, in case of something like what happened above.