What is even worse, only the "old" Raspbian aka Debian "Wheezy" aka Version 6 is supported. I upgraded my Pi 2 to Raspbian "Jessie" aka Version 7, and found out that the Mathematica package has disappeared. I asked Wolfram Support, was sent to this forum, posted a question about this issue and received no reply. :-(
So no, looks like if you want to use Mathematica on the Pi 2 then you have to stick with Raspbian "Wheezy".