About the Crossover Arc once it airs on ... I don't know if it comes Nickelodeon or Nicktoons first, whatever
I watched the final credits of the episode, and it includes the Ice Cream Kitty music video information alongside the info of the episode.
This makes me think that probably ICK music video is part of the crossover arc (not only on the DVD), and it would be included on iTunes inside the episode too.
The only thing we don’t know is if Nickelodeon/Nicktoons will air it on TV or not.