The pre-expansion patch launched today with the new demon invasion, the Dark Whispers event, Broken Shore, and of course Demon Hunters being playable. All of these you can access without pre-purchasing Legion except for the Demon Hunter part.
For those of you who do not care if you are spoiled (or have seen these before and want to watch them) – we have the in game cinematic sequences for the events. For those who do not wish to be spoiled, you have been warned.
The first 3 videos deal with the end of the Broken Shore event and the aftermath. The last 2 videos are during the Demon Hunter starting area.