I've worked a bit on the scale dialog for Krita. Neither the old one from the 1.x series nor the new one in current KOffice2 alpha releases were good enough. I've mailed a bit with Ellen which only confirmed that it is indeed a difficult dialog to get right.

In the end I reordered some items, so I hope it's a bit easier to figure out how to use it. I think it has become quite good, but judge for yourself. So much cool stuff coming in KOffice 2.0

Kross, the scripting framework, is one of the pillars new with KDE4. While the project started already a while back in 2004 it enveloped over the time to a rather big codebase. During the KDE4-process one of the main-goals was to decrease the codebase what can be even more difficult then writting new code.