A few days ago I posted a video and screenshots of Dalaran and how to get in there via a floating triangle crystal in Crystalsong Forest. Far above in the sky from where the crystal is you can see Dalaran. Well, many of the beta testers who had not previously visited Dalaran and completed the quest found out they could no longer click the crystal and get teleported to Dalaran.
This happened after the patch released three days ago. Today it was my turn to find out I couldn’t get back up there on my main character. The message the crystal emotes when clicking it says You can’t use the Dalaran crystal until you have used the Dalaran Crystal at least once. This sounded fishy to me. Reading between lines I figured out that an NPC might offer a quest where you get teleported into Dalaran, then when you talk to the Dalaran NPC in charge of teleportation she would give you the same quest I reported a few days ago, allowing you to teleport down to the crystal on Crystalsong Forest, to them beam you up, activating it permanently for you.
Well, I had to go back to Silvermoon to train Paladin spells. When suddenly, I noticed a quest mark in the mini-map when I arrived to Vengeance Landing (Horde). A Magister located at the Inn gave me the quest to go to Dalaran. The NPC casted a teleport on my character and I was teleported into Dalaran. For Alliance, that would mean you must find the NPC at Valgarde. Something I assume is that Borean Tundra might have similar NPCs giving you the same quest. So go check it out and get your ride to Dalaran. Make sure to grab your flightpath too on the east of the Dalaran mini-map once you teleport there.