You can grab the script from here
https://www.suse.com/communities/conversations/files/2014/10/multimediacodecs_sled12.tbz
I didn’t want to make the direct link public in the forums.
Check out the README for info on the new way to get the SDK - you don’t have to download the ISO now, you can just add the repos.
I submitted the post a few days before SLED 12 was actually released in the hope that it would get published on or very soon after the release date, but sadly it’s still marked Pending.