The developers have decided to support the next OpenSUSE for a longer time
OpenSUSE 13.1, a free and Linux-based operating system for PCs, laptops, or servers that you can use to surf the web, manage your e-mails and photos, do office work, and play videos or music, will become the next Evergreen version.The developers of OpenSUSE have decided that the 13.1 version will be the next Evergreen release, which is actually the next long-term support distribution.
“The openSUSE Evergreen team expands the lifespan of openSUSE releases by issuing security- and stability fixes after the usual 18 months. The team has kept selected releases maintained for an additional one and a half to three years.”
“The first Evergreen release was openSUSE 11.1. Current releases in the Evergreen maintenance program are openSUSE 11.2 to be maintained until november 2013 (a total of 4 years) and 11.4 to bemaintained until July 2014 (reaching over three),” reads the official announcement.
You have to keep in mind that OpenSUSE 13.1 hasn't been released yet and few milestone versions have been made available so far.