Back in 2012, Deadmau5 reached out to Armin van Buuren about doing an “open collab.” Armin van Buuren quickly replied and tweeted “deal! I'll be in my hotel in an hour.”
While the collab was highly anticipated by the entire EDM community, the deadmau5 subreddit declared that Deadmau5 got “bored of it” and announced that the collaboration was dead back in December of 2013. Not only did deadmau5 declare the song to be dead, but deadmau5 also attacked Armin's radio show ASOT and Armin van Buuren snipely responded.
While we're not sure if this collaboration will ever be fully released, here is a clip of the collaboration that premiered on ASOT.