Telepathy-Qt4 is a high-level binding for Telepathy, similar to telepathy-glib but for Qt 4.
0.2.0, the first shared-library release with stable API and ABI, was announced on 10th November 2009.
Development is done in the telepathy-qt4 git repository.
API documentation for the 0.2.x stable branch (somewhat incomplete, using the 0.3.x documentation is recommended)
Differences between TelepathyQt and Telepathy-Qt4
The older TelepathyQt library maintained by the Tapioca project only contains low-level 1:1 bindings of the D-Bus interfaces; the separate Tapioca-Qt library builds on that to provide high-level API.
In the same way as telepathy-glib, Telepathy-Qt4 provides both the low-level (1:1) auto-generated API, and a high-level API built on that, in the same library.