Update: A new post is here about the changes.
If you are one of the millions of people who use non LTS releases of Ubuntu and have avoided upgrading, that time has now passed.
Beginning with Ubuntu 13.04 Raring Ringtail, non-LTS releases will be supported for 9 months instead of the original 18 months.
The choice was made over a “rolling release model”, despite being popular in the community. At the time of writing, details are still emerging.
The blog post states “The developers want to make it easier for users of the distribution to get up-to-date packages on a regular basis without the need to perform explicit upgrades of the whole distribution.
The reduction in support for non-LTS releases from 18 to nine months should give the developers more time to concentrate on testing the packages to which users will be able to upgrade between major releases. No decisions have been taken, apparently, on how the up-to-date packages will be delivered to users; the Technical Board only decided to “enable users to continuously track the development focus of Ubuntu without having to explicitly upgrade”. The implementation details are expected to be worked out in the next few weeks.”
To learn about this change, hit the links below.