I have not investigated the QEdje-Plasma-Applets much, but here's how to get them working, assuming you compile your kde from svn.
Some info is on MoRpHeUz’s Blog.
Not enough for me though...
So here is a step by step walk-through.
You probably need libeet-dev or similar, I just got a distro package.
Get qzion and qedje:
$ git clone http://dev.openbossa.org/qedje/qzion.git
$ git clone http://dev.openbossa.org/qedje/qedje.git
Build and install the stuff:
$ cd qzion
$ qmake PREFIX=$KDEDIR
$ make install
Install qedje the same way.
Rebuild Plasma from kdebase.
Now the trick part - how to get the sample Edje files onto the desktop?
Take for example kdelogo.edj and save it somewhere.
Now simply open the "Add Widget" dialog from Plasma. Choose Install New Widgets->Install Widget From Local File...
Select your Edje widget. You will get an error message. Ok.
Run kbuildsycoca4. Now the edje widget is in the Add Widget list :)
Add the rotating K and be proud. No, I don't know why you should be proud either.
I added mouse interaction to the marble wallpaper, so you can spin your desktop now ;) but that's a different story. No super-pigs included this time.