Munch,
Though I can understand your pain, you're technically running an unstable server base. Gmod 13 is still beta, much like the github code in the link above.
You expect a stable(/production) ULib/ULX release for a server code base that's
still in Beta itself and may change even up to point of it's release?
I'm sorry, we're good, but not that good.
No developer in their right mind, especially working with the seeming manic insanity of Garry's change history, would release something before than and call it stable.
I've seen Garry make drastic changes to his lua engine within a week of major releases of his own beta code.
Now, Megiddo and Stickly may be able to give more timeline and update on getting things that aren't working working again, but, by no means will we make a 'stable' release until after the Gmod 13 release.
And, since you're reasonable new (at least as a member) around here regarding the life of our releases, our typical answer to your question;
"We release when it's done"