As promised, even though there has been lack of updates in public changelog, that doesn't stop Slackware team to work on updates in the private area. Robby Workman has been doing an extensive work in XOrg area and here are what we got in this changelog: a massive XOrg updates. Slackware-Current now uses a combination of XOrg-1.12, Mesa-8.0.2, xf86-video-intel-2.19.0. This brings the XOrg stack to the latest version available.
There are several packages that gets upgraded besides XOrg, namely tree, llvm, OpenSSH, bluedevil, libwnck, fribidi, and network-scripts.
Update (May 6): I see many people forgot to read the changelog and they just ran slackpkg update; slackpkg upgrade-all without running slackpkg-install-new and slackpkg clean-system to install new packages, such as llvm, freeglut, libXcm, libXaw3d (replacing xaw3d), mtdev, xcb-util-image, xcb-util-keysyms, xcb-util-renderutil, xcb-util-wm, and xf86-video-modesetting and remove removed packages such as scripts, xaw3d, xf86-video-radeonhd, xf86-video-sisusb, xf86-video-tseng, and xf86-video-xgi. As a result, they are left with no keyboard and mouse working when they entered desktop.
Please read the ChangeLog before upgrading packages in -Current. Make that a procedure :)