User blog comment:NasuHime/Umm...Guys. MIKU OPERA?!?!/@comment-5235303-20121126225719/@comment-5532114-20121127001057

I saw it on Tumblr a couple of days ago.

Of course I doubt we can count on anyone aside of Cryptonloids, since, you know, there is a Crypton label on those promo images, but that sentence

"No humans will appear onstage during the opera, even to play the instruments. Instead, Vocaloids will take their place, taking over every aria and recitative."

at least suggest there will be more of them than only Miku.