You probably were aware that the KDE team had released version 4.5.2 of their software compilation a little while ago. I had other things to do at that time, so you did not see a package set for Slackware until now.
Yesterday I talked to Pat Volkerding to see what his short-term planning looked like, and based on the conversation I decided to go ahead and build a set of packages for slackwarre-current (32-bit and 64-bit of course). Rest assured that Pat is working on something equally entertaining as building KDE packages 😉
Here they are, uploaded to my ‘ktown’ repository.
See the README file for installation or upgrade instructions. They are no different from any prior release. There is not even a single additional dependency to install this time, thanks to the fact that Slackware -current already contains KDE SC 4.5.1.