This:

Imagine nintendogs with this, you actually feelyng the fur. Profit.

So, of course this will not being what nintendo will do.

This:

I will say something that many people might not agree with, but I expect them to keep the resistive touchscreen. The reason being the precision of the stylus, which I don't know if they'll want to sacrifice since certain franchises need that kind of precision. I mean, yeah technically they make styluses for other types of touchscreens, but they are an extra expense and not all are very accurate.

As for what to add, I think they will go HD and with a second analogue input of some sort, etc. Basically the obvious stuff. Not sure what else to add really. Although I did have the thought that they could implement some phone features into the device, giving it talk (via headset) and text ability as well as a 4G or 3G data via a third party service. This could help sell the device to parents whose kids want some kind of phone device but the parents don't want to deal with the potential horror story of their child spending an unholy amount of cash on microtransactions. But that could be rather costly.

Inductive Screens are far more accurate than resistive screens and you can combine them with capacitive tech, like Seen on the Galaxy Note Smartphones for example.

on topic: I have absolutely no idea what Nintendo's up to.

Everyone had too much imagination. It'll be the N3DS, in HD. Maybe a second circle pad instead of a c-stick. That's it. No "free form" screen. No single screen. No "Vita TV" like console to connect to. No throwing away of BC for DS and 3DS after spending over a decade cultivating a playable library for them, much which has been made digital.

Just a dual screen handheld, with an HD, still 3D capable, top screen, dual analog, bumpers and triggers, and significantly more power than the Vita, but a little weaker than the Wii U. It's selling point will not be a new hardware gimmick. It will be a firmware gimmick; the unified platform. Same library on two consoles. That's it.

I doubt they will be one.in.a.traditional form. They market has shrunk.so much so quickly thanks to smartphones.

That would be Nintendo's most expensive handheld yet, so I would say a little bit more powerful than the Vita, since that thing is already a gen ahead in power compared to the 3DS, shame it has no games.

OMG Imagine if they kept dual screens and made both of them look like these with the pads and button on the bottom screen.

i like 4DS name better :(

I see no reason why it would have to be expensive. The Vita is $200 now, and that's with overpriced component like it's memory card. In two years, it'll be cost a lot less. There's no reason they couldn't get hardware significantly more powerful at $200 by that time, especially with the much cheaper memory Nintendo opts for.