If a lot of the people who might have been interested in the 3DS or NGP have already bought a smartphone, is spending 20 Euro a month or more for data, or bought tablets or PMPs in addition, then that extra $300 to start with a 3DS or NGP is a tough sell.
They've spent a couple of hundred already on a mobile device and may be spending a sum on mobile data, not to mention voice and SMS.
In addition, a lot of these people already have a PS3 or 360 hooked up to their HDTVs and have played a lot of the games that the NGP is going to feature as exclusives.
So how compelling will the NGP versions of Uncharted and LBP be to these people? I may not be representative but I've played versions of GoW on the PS2 and PS3, I got iPhone, will eventually get iPad but I never got PSP (bought it at launch and then returned it unopened) so never played the PSP versions of GOW and other PS2/PS3 games.
The NGP is enticing in some respects. Screen and size may be a good fit between my iPhone and iPad. But it would be the third device at best. I could see packing iPhone and iPad for trips but NGP may be left behind. Have a very short commute so I would most likely use NGP at home, where I already have PS3.
Maybe if the NGP had good browsing experience and had a lot of casual and non-gaming apps. that I use throughout the day on the iPhone, I'd carry the NGP along for the bigger screen (unless there's a good 7-inch tablet with a lot of the apps. I use). Then I'd rent or buy games on sale or used games, while reserving the full-priced games for the console.
Not a good NGP customer for Sony (enthusiastic about the NGP, buying lot of new NGP games) and yet, there must be a lot like me who's interested in AAA games yet have already invested in the ecosystems of mobile devices (games as well as non-gaming software).
Sony and Nintendo would like to have customers who buy both their consoles and handhelds and games for both. But the problem is, these customers are already among the buyers of tens of millions of smart phones and tablets sold each year. Maybe they could capture a number of those ready to upgrade their phone or tablet or the truly dedicated who'll buy every gaming product that comes out.
PSP sales were poor at the end. NGP will get a spike at launch but beyond that, the buying trends that worked against the PSP will be even tougher for the NGP.