Eric Hameleers has built the latest LibreOffice 4.0.3 for Slackware users. The package is built for Slackware 14.0, but they are usable for Slackware-Current users as well. For those who are still running Slackware 13.37, you should stick with the 3.6.6 release or upgrade to Slackware 14.0 to enjoy the current version of LibreOffice.
He has also managed to provide updates for steam client and several other packages in his repository. Check the ChangeLog for more information about updated packages.