Except that the console the PS3 is tied with for the month was Nintendo's Game Boy Advance--a last generation handheld. Also, the PS3 wasn't actually tied with the Game Boy Advance, it was slightly behind it. Seriously:
Specifically, the NPD statistics supplied to Gamasutra by the firm reveal that the Nintendo DS dominated the month's hardware sales, with 471,000 units sold, closely followed by Nintendo's Wii console, which sold 360,000 units in April, despite continuing console shortages.
The Xbox 360 sold 174,000 units for the month, slightly behind the PlayStation 2, which managed 194,000 for April, and the PlayStation Portable, which sold 183,000 in the month. However, the PlayStation 3 again slumped, with just 82,000 units sold in April, again behind the Game Boy Advance, which sold 84,000 copies.