For updating the release notes for Lenny , what about:
There are not huge changes in the KDE Desktop Enviroment from the version
shipped in Etch. Lenny ships an updated translation and service release of KDE
3.5 that is a mixture between 3.5.9 and 3.5.10. Modules labeled as version
3.5.9 are updated and they include mostly the same than the tenth revision.
In overall, Lenny ships 3.5.10 without the kicker improvements shipped in
kdebase and some bug fixes in kdepim.
Lenny will be the latest stable release including a KDE 3 series environment.
Proofreading for english natives is totally welcome :D
 Current stuff is from etch: