The new feature to KDevelop 4.4.0 is a QML/Plasma-based welcome screen. The welcome screen should help newcomers, but isn't any revolutionary new feature for KDevelop. Beyond the welcome screen, there isn't much else.
The KDevelop developers say the noteworthy changes for 4.4 is a bit small but there's been lots of bugs fixed and optimizations to existing code-paths for the open-source IDE.
The KDevelop 4.4.0 release announcement can be found at KDevelop.org while embedded below is a video about the new welcome screen feature.
At least it sounds like KDevelop 4.5.0 might be a bit more exciting and the earlier KDevelop 4.3.0 release from a few months back brought basic C++11 support.