Slackware has released several updated packaged that are considered security update, but no advisory has been released yet (probably in the next few hours). They are Apache, Firefox, Thunderbird, and Seamonkey. The update were released in different version. For example, Slackware 12.2 only received Apache update, while Slackware 13.0 and later received Apache, Firefox (3.6.x branch) and Thunderbird.
Slackware 13.37 users can now be relieved as Pat upgraded Firefox support to 6.0.x branch. Unfortunately, the same situation doesn't happen on Thunderbird. It's still using 3.1.x branch for now.
Slackware-Current received the biggest update with Apache, Firefox (6.0.x branch), Thunderbird (6.0.x branch), Seamonkey, and there's a new upgraded package for OpenSSH 5.9 which has been released few days ago plus one new package in testing/ for Firefox 7 Beta 4.
There's still no sign of major changes happening in -Current, but we know that Pat is up to something and he plans to announce it when it has passed his thorough testing phase. I'm guesing he's aiming for KDE 4.7.x and XFCE 4.8 for the this release and he must deals with all the dependencies before uploading all the packages to the mirrors.
We will have to wait for that time to come