A recent listing on a US retailer's site suggests that Samba De Amigo will be the first Wii retail title to utilize the Pay to Play system.
The boxart, on Gamestop, features the Red Nintendo Wi-Fi connection symbol, a sign of the Pay to Play feature that mainly refers to paid downloads, as in Wiiware title Final Fantasy; Crystal Chronicles.

Nintendo hasn't been completely clear on the requirements of the Pay to Play system, so it is largely unknown as to how it could be used here.