Now that everyone has had some time to defeat the baddies of Highmaul, including Kargath Bladefist, Blizzard has announced the dates for the next raid instance. Blackrock Foundry will open up to Normal and Heroic difficulty on February 3rd, 2015 and Mythic level one week later. They are also releasing into the wilds of Draenor the next World Boss, Rukhmar.
The new raid finder for Blackrock will require an increased ilvl of 635, and it will have four wings, with the last wing being Blackhand.
For complete details on the release schedule, take a look at the full post from Blizzard.