Please note that this packages are built against Slackware-Current, so an upgrade to -Current is recommended if you don't want to have problems with some language binding (mostly with PERL).
There's also some changes in the way you install these packages, so please READ the README carefully before you attempt to upgrade/install your new KDE 4.7.0. Those README were created to ease your migration, so please don't waste Eric's efforts.
Eric also mentioned some note about problems that you might encounter if you use Slackware 13.37. KWin requires Mesa 7.10.2 as their minimum requirements and Slackware 13.37 does provide that package, but it's available on testing/, so if you want to try KDE 4.7.0 in Slackware 13.37, you MUST upgrade to mesa-7.10.2.
You can get the packages by getting it through several mirrors: