Key features of the KDE 4.10 updates to the Workspaces, Applications, and Platform stack include more KDE Plasma components being ported to QML, a new version of the touch-typing application KTouch, improved usability, stability improvements, and performance improvements.
Bringing more of KDE's Plasma to QML will make it easier for the ultimate migration to Qt 5.0. Using QML will also lead to a "more elegant user-interface."
Other KDE 4.10 Beta highlights include a new screen locker, a new print manager, support for animated wallpapers using QtQuick, color correction support, improved Plasma notifications, and plenty of other changes throughout. There's also more coverage in Features Being Brewed For KDE 4.10.
The KDE.org press release outlines some of the other KDE 4.10 Beta 1 changes.
The KDE 4.10 release schedule puts the final release of this desktop environment for the end of January.