Debian/PowerPC packages of KDE2 are now built and are apt-able from http://southpole.penguinpowered.com - just add the line
deb http://southpole.penguinpowered.com/debian woody kde2 to your /etc/apt/sources.list. Currently this is an 8/27 snapshot (just after beta4), I'll be updating it whenever I get time. The stability of this build is pretty good, one bug you may catch is that you may need to manually run kbuildsycoca to update the menus and mime-types after installing due to a bug in this version of kded (since fixed, but I haven't updated the packages yet). The packages should be fine on potato (stable) as well. Enjoy, and thanks to Ivan E. Moore of the kde linux packaging project for being so helpful, and to all the KDE developers for making a desktop that rocks. aRts (the soundserver) does not currently work on PowerPC, so many of the multimedia apps will be silent - I have some fixes locally that make it work, but they need more polishing before they go in.