Well, it's good that Ubisoft is taking quality control a little bit more serious now, although they still need to work on communication to the general public.
Patch 4 for Assassin's Creed Unity was scheduled to come out today. But on their update blog, it has been revealed that the patch will not be available today, contrary to initial statements made by Ubisoft. Specifically, they have indicated that they are dedicated to "delivering major performance improvements, which requires that we refurbish the Paris map and that will take a few more days to hit the high level of quality that our players deserve". No new projected date has been given at this time, despite the statement indicating a few more days. Within the comment section of the blog, the moderator indicates that the estimate of a few days is "very rough", which indicates that it is uncertain when the patch will truly hit end users hands.
Specifically, on December 11th, the update page indicated that the patch would address issues with stability and performance, as well as online matchmaking and connectivity. It would also include various other fixes and improvements, although those specific improvements were not mentioned. The community is vocally upset with the decision, most likely due to the confirmation of the release date of the 11th, and the notorious state that the game launched in. It has been mentioned that the Club Competitions, an in game event to obtain some of the Legendary equipment, will be coming online shortly after Patch 4 is unlocked.
Ubisoft has come under a lot of fire recently due to the review embargoes revolving around Assassin's Creed Unity and the lack of review copies for The Crew, and in particular the lack of quality control seen with some of their releases. The infamous floating eye and mouth bug, along with performance problems on all systems has caused a backlash in the community, and questioning Ubisoft's commitment to quality. This, along with the leak of the next game in the franchise being currently in development, has Ubisoft on its toes while it deals with the backlash coming from frustrated consumers who want to simply play the game they bought originally.