Just picked this up today, and I wanted to offer my initial thoughts on the game.
As some have noted, it seems as though DLC is not supported, even though it is advertised on the case cover. There is no integration with the iOS game either.
I haven't tried it myself, but apparently the online multiplayer lacks a lobby system, and has no way to set up anything but random online matches.
I played about an hour of the single player story mode, which was fun. I enjoy watching the cutscenes and the story as it unfolds in between fights.
On the packaging only the GamePad and the new Pro Controller are shown as supported, but I can confirm that you can use the Classic Controller Pro attached to a Wii Remote, as well as the Tatsunoko vs Capcom fight stick that similarly plugs into a Wii Remote. I did not try but I assume that the Classic Controller would also work.
More thoughts to follow as I dig into the game over the next couple of days.