If Nintendo has the market share, they'll get the games, and people won't care if it isn't HD. And if the PS3 got a PSThwiimote, it would still be like getting 2 consoles for the price of 2. And actually, they'd be behind in developing Wii Sports-esque software, too. That applies to 360 also.
"[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.