Rolling Release means that there is no definite release date. The only quality assurance that will be done is that maybe some kind of snapshot is defined.
If you look at debian, you find both models.
- stable is an ordinary release branch.
- testing is the development branch. It is renamed to stable if it gets released.
- unstable is a rolling release branch.
13.04 / raring will be released as planned.
The beta ISO image will always be beta, because it contains a snapshot of packages that existed at a particular time, and Ubuntu 13.04 was beta at that time. (It is also beta now, as you know, though it will be released soon.)
Any version of Ubuntu can contain bugs but development versions (alphas and betas) are expected to have more bugs than released, stable versions. It's possible for a bug to cause a problem installing updates. However, except for possible beta bugs getting in the way (which only rarely happens), a system installed from the beta ISO can be updated successfully.
After 13.04 is released, an installed beta version will become the stable version simply by installing updates (in the Software Updater or by running sudo apt-get update
, sudo apt-get upgrade
, and, if any packages are held back, sudo apt-get dist-upgrade
). For more information about this, see:
So, in summary:
- Your beta ISO image will always be beta; it will never be supported as stable installation media, and the system you get by installing it will always initially contain unstable packages. (And they'll be old, obsolete unstable packages if you install from the beta ISO after 13.04 is released.)
- The actual operating system should, barring corner cases where a bug prevents it, simply upgrade seamlessly into the stable version, once the stable version is released.
If you're going to do new deployments of Ubuntu 13.04 after it is released, it's a good idea to obtain a copy of the stable release ISO for it. (Which doesn't exist yet, of course, but will once 13.04 is "released.")
Best Answer
Those rumors where unfounded, Ubuntu's plans to become a rolling distro never saw the light of day even if they were ever discussed internally.
That news that you saw back in 2010 triggered a response from Engineering Director of Ubuntu Rick Spencer.
On his blog post he clearly says
He goes further down saying
What he refers here is the +1 maintenance team which exist to ease the pressure on developers and make further releases easier and less stressful for them. It is not to be confused with a rolling release.
After that there was not further information or news about Ubuntu becoming a rolling release. I am assuming that this can be answered better by someone from Canonical / Ubuntu. But since those rumors where proven false and there is no further information about this I can assume that a rolling release is not on the planning table.