In an interview with Gamedaily.biz Sony VP Jack Tretton spoke about the battle for market share between the Nintendo DS and Sony's PSP. Looking at the early adopter rates of the two systems he believes Nintendo may be losing their core gamer audience instead of expanding it. Here is an exerpt from the interview:

"[Nintendo and their DS] are appealing to the same audience that Game Boy has always appealed to. And if you look at the adoption rate of the DS over the first 17 months, not only does it trail the PSP but it also trails their other platforms ... They're potentially losing some of their core audience and they're not really expanding beyond that, and we think we're expanding into a completely new audience as we did with PlayStation ... we'll dip down to the younger consumer eventually, and we'll ultimately appeal to that vastly Earth wide audience we carved out with the original PlayStation."

Sounds like he thinks Nintendo is trying to expand the market where Sony already did with the PlayStation.