They just finished announcing it at an event at Gamescom, in the Legion bar. Game director Ion Hazzikostas was there to do so, and then hit up a community stream to explain the details. There will also be a small raid, new outdoor content and more.
For the nitty-gritty details about "Return to Karazhan":
- It's a massive five-man dungeon with all the same bosses as the original.
- There will be a small raid in the same patch with content aimed for between the two already-announced raids.
- New outdoor content too.
- Will hit PTR just after Legion launches.
You can also watch a full trailer for the patch below:
Hazzikostas also commented on recent content drought and further concerns going forward:
- Expansions will no longer be targeted for one a year, or one every 18 months. They're done when they're done, and live game content will always be prioritised.
- Raid tiers are going to be around 4-5 months, not counting Karazhan's mini-raid which will server as a stepping stone.
- Despite what it looks like, this isn't them blowing everything they have early (again) - "we've got you"