Comment 10 for bug 274187

@norsetto: there are pros and cons of both ways of doing things. We decided to use this scheme in gutsy - after careful thoughts and even after trying the -trunk/-snapshot thing. There are pros and cons for bot approaches, but it is well understood that we can only provide a seemless and pleasent user-experience when not going the -trunk approach.

 1. users should never be accidentially upgrade from an (almost) stable release to a late alpha
 2. profiles are not interchangable, meaning you cannot switch up and down for major firefox versions without a) forking the profiles and b) risking dataloss if you use the same profile directory. Further, the main browser must not have a profile directory that isn't the same as upstream profile directory. Its a bit lengthy to explain here what we do and why that is lot of easier to do if we use versioned packages and meta packages, but if you want any details ping me on irc.
 3. its not only -trunk. its also -old (like in hardy we didnt have a preview packages, but only a legacy one). All this makes it quite complicated and moving all the bits from package to package is just wasted effort and requires constant conflicts/replaces transitions.

@sispoty: the transition is done through the meta packages. so people that install "firefox" opt-in to be always redirected to the latest stable firefox-x.x package. People that don't install the meta package will not be transitioned, but in the ends thats their decision. Maybe we could introduce two more meta packages called "firefox-edge" and "firefox-legacy" ... that would be similar to the meta package and would allow users to opt-in into either always running the bleedging-edge (firefox-edge) the main browser (firefox) and the old browser (firefox). In case we dont ship anything older than the main browser, we would make the firefox-legacy meta package poiint to the main package (or in case we dont ship a bleeding edge package point firefox-edge to the main browser).