As usual for these KDE monthly point releases, the KDE 4.12.2 Applications and Development Platform updates this month just incorporate a number of bug-fixes. This month is rather light though with having just 20+ recorded bug-fixes compared to some months that have seen much more activity. The applications focused on this month for fixing were Kontact, Umbrello, Okular, Konqueror, Dolphin, and other K applications.
KDE Plasma Workspaces 4.11.6 is now also the latest version of the desktop interface ahead of Plasma 2 with KDE Frameworks 5 later in the year. It too has bug-fixes with this release.
More details on KDE 4.12.2 can be learned from the release announcement issued at KDE.org.