First off -- the PUD now lives in the KDE Subversion repository! It's at svn://anonsvn.kde.org/home/kde/trunk/playground/libs/popupdropper -- it builds with CMake and acts as a standalone library. Included in there is a testapp that you can build with qmake that I use for my testing and that you can use to check it out, which I encourage. Amarok now uses the PUD pulled in as a svn:external, which means Amarok is now very easily synced with updates I make to the PUD.
About a year ago we had an issue in Amarok 2 development because we wanted to be able to move portable device track access into collections (this is happening with Alejandro's GSoC project), but we couldn't figure out a good paradigm for accessing the various device specific functions. There were some other concerns too, about the right-click menus getting too overloaded, making it hard to find common functions.