Quote Originally Posted by Nadirah View Post
Mythic is delayed release, but so is LFR. Normal/heroic release immediately. LFR is a week or so after. Mythic is a week after that.
Normal/Heroic release immediately. Mythic is one week later.

Raid Finder (LFR) is broken up into wings (1-3 bosses per wing). Blizzard's current philosophy for Raid Finder (due to comments/complaints from the raiding community over the course of the previous expansion) is that only people who should ever have any reason to run it are people who will never touch any of the higher difficulties. The first wing releases alongside Mythic, and each successive wing is staggered by a couple of weeks, so it takes a month or two for the whole thing to be available through WoW's equivalent of the Duty Finder.

To use the current raid as an example:

06/23: Normal and Heroic available.
06/30: Mythic available. Raid Finder bosses 1-3 available.
07/07: -
07/14: Raid Finder bosses 4-6 available.
07/21: -
07/28: Raid Finder bosses 7-9 available.
08/04: -
08/11: Raid Finder bosses 10-12 available.
08/18: -
08/25: Raid Finder boss 13 available.