After a long awaiting I am glad to announce that the first release of NetworkManagerQt is available for downloading. The (short) announcement is available in NetworkManagerQt's project page.
Both NetworkManagerQt and ModemManagerQt are dependencies for the new Plasma NM applet. There are still rough edges to polish in NetworkManagerQt, specially in documentation, we are going to fix them in the next releases. Talking about documentation it is available through doxygen (read project's page for instructions). There is also two example programs to list device's properties (ip address, gateway, static routes, dns, etc) and to create wifi connections.