Actually, my Firefox it's advicing me to update. And I'm not on the nightly, developer or beta channel.

Are you sure you're not on the beta channel? Coming from Firefox 4, that channel stuff was under the hood. If you used Firefox 4 beta, then you're probably on the beta channel (you can check in about:config looking at app.update.channel)

Strange, mine (4.0.1) doesn't. There's something broken either in the update routine or in your Firefox. The beta is not supposed to be recommended to users of a release version.

Yeah, I'm also very confused. While I think it's a good idea to be pushing relases more often, this is way too often.

Here's the about Firefox dialog http://i.imgur.com/cDbN1.png and the update request http://i.imgur.com/4SYRI.png