Sony only owns 1 IP that has EVER sold 10 million copies of a game. Gran Turismo. Nintendo just hit the 10 million mark with Nintendogs. By May, they'll hit it with Pokemon and NSMB. I'm betting Wii Play crosses the mark too (obviously Wii Sports will). 10 million is a mark only about 25 games have ever hit; Nintendo seems to be doing it regularly. Sony only owns 1 IP that has EVER sold even FOUR million copies of a game. Gran Turismo (2 times on PS2) Nintendo has hit the 4 million mark with Mario (6 times), Mario Kart (3 times), Zelda (soon to be twice), Smash Bros, Brain Age (2 times), Pokemon (many times, no matter how you count it), Nintendogs and Animal Crossing since the launch of PS2. Now... Get into the 3 million sellers... And 2 million sellers... And Sony's list grows substantially. But overall... Without 3rd parties they crumble like a house of cards, compared to Nintendo.
"[Our former customers] are unable to find software which they WANT to play."
"The way to solve this problem lies in how to communicate what kind of games [they CAN play]."
Satoru Iwata, Nintendo President. Only slightly paraphrased.