Quarter 2 tends to usually mean: by end of the last moment possible of that quarter, meaning end of June.
Of course could be different with Canon, but these quarters are newspeak for release dates to look earlier than they really are, in other words, people would be disappointed if someone would say "it is 30th of June 2012", but when it is already Q2 2012, it feels almost like February despite it still is in end of June. They have read their Orwell's 1984 well.