Nintendo: Wii Has 9.5M Install Base in United States; Mario Kart Wii Was No. 2 Game in April

Though sales-tracking firm NPD Group will not release April's data for another hour, Nintendo has already chimed in with some results. According to the company, the Wii ranked as the month's top-selling hardware with 714,000 units sold in the United States across April and Mario Kart Wii placed a...