The following is a list of notes on building MATE on Slackware -current:

Tue Jun 11 00:41:15 UTC 2013
Pat has rebuilt xdg-utils in Slackware-Current to properly support MATE DE, 
so xdg-utils patch is no longer needed in Slackware-Current, but running 
these two commands as normal user are still needed to set caja as the 
default handler:

xdg-mime default caja-folder-handler.desktop inode/directory
xdg-mime default caja-folder-handler.desktop application/x-directory

please make a backup of your $HOME/.local/share/applications/defaults.list
before executing the above commands

Tue Mar 26 02:06:35 UTC 2013
Another note about the addition of dconf to Slackware -current.  If you
previously built MATE packages with the dconf in the MATE SlackBuilds /deps
directory, you'll need to rebuild the following packages using the new dconf
in -current:

base/mate-control-center
base/mate-panel
base/mate-settings-daemon
extra/mate-terminal

Sun Mar 24 04:48:35 UTC 2013
Pat just added dconf to Slackware -current and dconf is included as a
dependency package in the /base directory.  So, if you are building MATE on
-current with Pat's new dconf installed, you shouldn't need to build the dconf
package in the MATE SlackBuild repository.  And if you are using the
mate-build-base.sh script, then please edit that script and remove line 52:

dconf \

And then proceed with running the script.  Please report any issues.  Thanks!