One way in which KRN is not multithreaded, is in that it is done using GNU Pth, which is not "real" multithreading, but cooperative userspace multithreading. Of course that if I had to make KRN reentrant and threadsafe, it would not be multithreaded in any way.
The other way in which KRN is not multithreaded is that it is not fine enough in its granularity. There are chunks of things which don't spawn threads, and lock the UI thread, thus locking KRN. But those are easy to fix: wait until someone complains it blocks, then make it spawn and look as a responsive developer ;-)
Also, I ported kdestudio's dockwidget back to KDE 1, and am adopting it to do useful MDI-like things (ie: docking, not real MDI).
Finally: the report progressing framework is there. All that's needed now is make it do progressbars instead of printing on the terminal, and make it work on all long actions...