The newest version of Ubuntu is a big one, but not for the usual reasons. With Ubuntu 13.10 (aka Saucy Salamander) coming out tomorrow, the desktop and server editions will get some upgrades as always. But the biggest change is that Canonical is delivering the first stable version of Ubuntu for phones.
Beta versions of the mobile Ubuntu have been available to test for months, and now version 1.0 will be ready for supported devices, namely the Galaxy Nexus and Nexus 4 phones. Preview versions have also been running on the Nexus 7 and Nexus 10 tablets, but Canonical isn't quite ready to declare Ubuntu stable for those larger touchscreens.
Ubuntu 14.04, slated for arrival in April 2014, is Canonical's target for delivering an operating system that runs on everything, including phones, tablets, desktops, and servers. Phones preinstalled with Ubuntu should also ship sometime in Q1 or Q2 next year, assuming Canonical can get the right deals in place with carriers and hardware makers.