Ubuntu 12.04.3 LTS Precise Pangolin has been released a while ago. It comes with some security updates and corrections, some high-impact bugs fixed, so the user has to do fewer updates.
Also, other Ubuntu flavours have been updated, including: Kubuntu 12.04.3 LTS, Edubuntu 12.04.3 LTS, Xubuntu 12.04.3 LTS, Mythbuntu 12.04.3 LTS, and Ubuntu Studio 12.04.3 LTS. For more information, see the official announcement.
Among the changes brought by Ubuntu 12.04.3, Rhythmbox has become the default music player, GNOME has been updated to GNOME 3.4.2, LibreOffice 3.5.4 has been installed, the IcedTea plugin has beeb removed, the kernel has been updated to Kernel 3.8. Also Firefox 23, Chromium 28, VLC 2.0.8 have been added to the system.
If you are a user of Ubuntu 12.04, to upgrade to the latest version, just do:
$ sudo apt-get update
$ sudo apt-get dist-upgrade