Qt 5.2 brings full support for Android and iOS, on top of its existing support for BlackBerry, Jolla Sailfish, and Ubuntu Mobile devices (plus the emerging Tizen support). Digia has also announced today a technology preview of Qt for Microsoft's WinRT.
On the desktop side, Qt 5.2 has improvements to Qt Quick Controls, enhanced Qt Widgets, improved accessibility, Bluetooth Linux support, rennovations to Qt QML and Qt Quick, and there's now the Qt Creator 3.0 IDE.
More details on the Qt 5.2 changes can be found via the Digia release announcement and this earlier article going through the new features of Qt 5.2.
Next up will be the Qt 5.3 release and it's tentatively planned for release in April with a big focus on performance and stability.