I have just completed a big upgrades to 12.0 RC1 on my laptop. Everything works fine on my laptop (Huge thanks to Patrick Volkerding and all Slackware-crew who made this process easy and smoothly). I upgrade most of the packages (except for packages which i didn't use) and install most of the new packages introduced in this RC stage and do a kernel compilation (upgrade to 188.8.131.52 manually) and it worked just like before, except that the packages has been upgraded with the latest version.
After seeing the Changelog, i didn't surprise to understand why the Changelog never gets an update. It's not because the team is stopping the development, but instead they test each package to ensure that it won't break anything and it did. So far, i didn't have any problems yet (and i don't plan to start with another problem), except for minor problem (LILO which requires dm-mod to be loaded before running /sbin/lilo or you will find a warning message).
Thank you again for Patrick Volkerding for the RC1 and i'm waiting for another RC before a final release comes out sometime in the future