I have been trying to use Nokia Qt SDK to package my Qt app. However, at the moment it seems that using the Scratchbox environment (Maemo SDK) is the only possibility if you want to create a source package for upload to extras-devel using the Extras Assistant. The QtCreator version (2.0.0) included in the current Qt SDK does not e.g., take changes to the debian/rules etc. files into account (however, the latest 2.0.80 snapshot seems to fix this). There are still obstacles to using the Nokia Qt SDK for creating the deb package; for instance, there are problems with satisfying certain build dependencies needed for the autobuilder.