WayForward just posted this little gem on their official blog:
Good news everyone! Shantae for Virtual Console has been confirmed for North America, Europe, Australia, and New Zealand. Look for Shantae on the Nintendo 3DS eShop at the tail end of June, just in time for your summer road trip. We’ll keep you posted as more details emerge.
I would guess we’ll see this show up just before the new Shantae and the Pirate’s Curse launches on the 3DS eShop.