Firefox 5 has been released today, so I want to know when Firefox 5 will be in the official Natty repositories. I don't want to upgrade using a PPA.
You wil get firefox 5 in the official channels in the next 24 hours.
If you want it before that use the PPA. It's easy and it is fairly safe. If you change your mind about PPA check out How do I install the latest stable version of Firefox?