The touch-friendly desktop interface has a new "Files" file manager that classifies files using Nepomuk and is more search-driven rather than using traditional folders, Okular Active as a Plasma Active e-book reader, and there's now Calligra Active and Kontact Touch as new ports. Plasma Active 3 has also been ported to run on the MeeGo-based Mer Linux operating system.
The KDE Plasma Active team is currently drawing up plans for migrating to Qt5 and the eventual KDE Frameworks 5 release.
More details on KDE Plasma Active 3 are available from the mailing list announcement. There's also the KDE.org press release.