NJ5 on 14 December 2008
I've checked a few times throughout the Wii's lifetime, and Wii Play has always maintained a 40-50% attach rate. So unless some situation changes, it should be pretty simple to estimate its sales in the future.
A changing situation could be for example some decision regarding Wii Motion Plus changing the benefits of getting Wii Play, or some new Wii Play coming out.
My Mario Kart Wii friend code: 2707-1866-0957
