Mad Catz first displayed the Tatsunoko Vs. Capcom fight stick in San Diego, gauging fan reaction to the design. Apparently fans reacted well, as it's now up for sale on the GameShark store for $79.99. I'd say it was a preorder listing, but I don't see the words preorder anywhere in the item description, even when I went through the majority of the checkout process.
It's a lovely stick, and as it connects to the Wii remote, it's also wireless, which is nice. Considering the alternatives available for the Wii, I'd say it might be your best bet for a Wii arcade fighting controller for quite some time.
Tatsunoko VS. Capcom Arcade FightStick For Wii [GameShark Store - Thanks Raphael!]