I have a very good news - Cool Reader 3 was launched on the k4NT, here are screenshots and some information in Russian language https://code.google.com/p/cr3runner/wiki/CR3OnKindle4NT
Here you can read guide how to run it (in Russian too) https://code.google.com/p/cr3runner/wiki/PrepareKindle
Using this guide you can try to lounch another aplications (fbreader etc) using kindlet instead of launchpad.
If someone will be intrested, i can make simple translation of the guide, or you can try to speak to the author here https://groups.google.com/group/pvnrunner?hl=ru
I already installed cool reader and it works pretty good! Now i am trying to lounch fbreader.