If you look at -Current's changelog today, you might get excited that Slackware have supported XOrg 1.14 in -Current and it will be used in the next Slackware release.
But, it comes with some problem, especially for those who are still using legacy NVidia drivers, particularly 304.xx branch. The previous version 304.64 is stable enough, but it doesn't support XOrg 1.14 ABI. I tried to use IgnoreABI option in xorg.conf, but it still failed, so i guess i have to upgrade to newer NVidia driver, 304.84. But this driver has one problem: it caused a blank (black) screen when you logged out from your DE (desktop environment, such as KDE) back to terminal (TTY).
Some people have reported this back to NVidia (this and this), but there are no permanent fixes for now. We shall wait for NVidia to release a new version which solved this problem. They have filled a bug ID of 1253539 in their bug tracker.
PS: Some people who used newer driver, 313.xx also suffer from this bug as well, so the bug is likely to affect all driver (i can't reproduce it on all version as i only have one machine which is using NVidia GPU).
In the meantime, there are two solution:
- Stay with XOrg 1.13 for now until NVidia released a new version
- Upgrade to XOrg 1.14, but you will have to shutdown/reboot from your DE using konsole/terminal instead of logging out back to TTY. Also, don't switch back to TTY for now.