Recently on Slackware ChangeLog, Volkerding wrote:
Tue Jan 27 14:33:35 CST 2009Hopefully Slackware 13 will integrate KDE4 and I will be able to enjoy the new features and eye candy.
KDE 4.2.0 is released -- congratulations to the KDE development team for such
an amazing job on this beautiful and highly user-friendly desktop environment!
Thanks also to Eric Hameleers, who did a ton of work getting KDE 4.2.0 ready
for Slackware. Once again (for now), these packages are compatible with
Slackware 12.2. Enjoy! :-)