Here's a Youtube promo video about this:
http://www.youtube.com/watch?v=b6iqoUdtIqk
Looks like there's a bunch of Phantasy Star titles included, even PS I-IV.
But even if there was a poll I guess it's closed by now, since this event already took place on March 30th, 2013 in Japan. In the same youtube video description it says that all attendants with the tickets will receive codes for obtaining various items and 4 BGM discs. So the whole concert will stretch onto 4 CDs. If this is the real thing, than it could be the true arrangement release that all Phantasy Star fans were waiting for.