During implementation of print for our new generation of GIS.lab Web, our core developer Marcel came with very interesting proposal of interactive work with map content inside of print template produced by QGIS, which I haven't seen anywhere else.
The main idea is, that once print is activated in GIS.lab Web, it will download raw print output from QGIS Server using GetPrint request and will allow interactive visualization of map content directly in this template. You can zoom, pan and rotate map and see exactly how the result will look like. To get the better idea, see video below.
Print template in QGIS Print Composer
Print template in GIS.lab Web
Video presentation of print in GIS.lab Web
Marcel and Rasto, thanks for very good work !