14 DAY TRIAL // The AMD Catalyst 15.3 Beta driver was made available a few weeks ago, but only for the Ubuntu distribution, which was rather odd. In any case, the drivers have been backported to Ubuntu 14.04 LTS as well.
The fact that the Ubuntu developers have ported the official AMD Catalyst 15.3 Beta to Ubuntu 14.04 LTS should not surprise anyone, especially since the drivers were made available for this particular distribution only. There is no information about any of the upcoming AMD releases, and it's difficult to know what to expect from the hardware company. It's no a reliable and constants source of drivers, and this is a well-established fact in the Linux community.
The new AMD drivers that have landed for Ubuntu 14.04 LTS users have been accepted into the proposed repository, and therefore, they are still being tested. They will soon be available for everyone, which makes this a very interesting development.
Ubuntu distributions don't usually pack the latest drivers
If you ever had an Ubuntu distro, you will know that you don't usually find the latest drivers in the repositories, and never Beta ones. The fact that the AMD Catalyst 15.3 Beta driver has been made available by default in the repos and that Ubuntu 14.04 LTS users will also get a chance to use it is a really good thing.
It might signal a change in the way Canonical has been dealing with the driver problem, which seem to get updated much faster than they used to. Two or three years back it was OK to update the drivers in the official repos every few months, but ADM and especially NVIDIA have greatly increased the frequency of the updates for their drivers.
AMD Catalyst 15.3 Beta drivers are proprietary, and you will have to install them from the official repos. If you already have a version of the AMD drivers installed, the system update will bring in the new versions as soon as they become available for everyone.