Kids are smarter now than they were back when I was a kid, as far as electronics go. Also, a product announced at E3 isn’t necessarily going to launch at E3.
At this point it isnt about the brand, its about the product. Sony has more than one TV on the market, Honda has more than one car, Motorola has more than one cell phone, and Nintendo will have more than one handheld.
Remember, the jump from Game Boy Advance to GBA:SP was just a year apart, and it was mostly a stylistic upgrade. The GBA:SP has been out for a while now, long enough to see a price drop even. The next Game Boy is going to be what Nintendo sees as the PSP competition.
I dont have any specific inside info, however, it has been what Nintendo has stated in the past. That said, the PSP and DS are currently both awesome handheld consoles. The DS game experience is definately a unique one, and the PS has the wow factor of next gen graphics on a portable.
I for one dont get why people feel the need to get on the bandwagon for one or the other!