Yes, it’s official, November 13th, this year!
No official note on the European site though. 🙁
Seems cool, but only half of it is working. Some things I did are not reflected in the achievement page.
The stats tab is clickable, but pretty much everything is still set to “0” or NYI (not yet implemented).
After tonights 240Mb patch, you can now “learn” all mounts in your bag, and once learned, they’ll dissapear from your bag, creating additional space.
You can summon your mounts (and non combat pets) from Character -> Pet -> Companions/Mounts tab.
Also the first part of the Hunter’s pet talent tree has been added.
And yes, a flying mount for the Death Knight!
Quest log seems bugged, and you cannot open it anymore using your mouse. Use <L> instead.
A lot more info has been added on MMO-Champion.
Here are the patch notes (little or nothing seems to have changed from previous patch notes):