Lars Knoll is beginning to work out the Qt 5.2 plans at Digia with the delayed 5.1 release being imminent. The hope is to have a release target of Qt 5.2 in November, so there's time to work around delays prior to Christmas.
New features for Qt 5.2 are expected to include a new QML engine that's going to be merged soon, full Google Android and Apple iOS support (there's initial support for iOS and Android in Qt 5.1), Qt Quick Controls for touch-based device support, and adding some of the mobility modules back into the list of supported modules.
Qt 5.2 might also contain the Qt 3D module along with the Qt Mac Extras and Qt Win Extras modules for additional functionality on the respective platforms. Lars has also proposed deprecating the Qt Quick 1 and Qt OpenGL modules for the Qt 5.2 release. Qt Quick 1 has been replaced by Qt Quick 2 with better features and functionality. Most Qt OpenGL functionality is now offered by Qt GUI and Qt Widgets while other missing functionality can be filled in.
The initial discussion about Qt 5.2 features can be found on the Qt development list.