just a bigger screen 5.2 or 5.5 i would love 6 and it is fisible, ...and because of this size smaller bezels!nintendo would think that this will sacrifice the speakers volume...but just see those on smartphones ,so small and so loud ,even a one speaker ,3dsxl speakers are awful...dsi xl had the best:Pi have an idea, what about vertical rectangular speakers ?also fhd ,or 2k or 4k

The way things are going there won't be another Sony handheld, unless it has a surge or some crazy legs (like the PSP in Japan).

Also are not the games the most important things?

1. Add 3D movie service
2. Better d-pad
3. More cellphone features and apps , like rumble supported notifications, SIM card support, phone service, iTunes, etc...
4. Works as a Wii U Gamepad, or a gamepad for Wii U2.
5. Cross platform support.

I think if they stay with a similair design it might have a foldable screen. The technologie is there, and it would allow the device to have a very large screen but still fit in you're pocket when closed.

3G, Triggers and Bumpers would be a waste...pretty much agree with everything else !

HD screen aroud 720p (or slightly lower than that) is the most important thing for me....but it shouldn´t be 1080p. I don´t want a repeat of the Vita situation where the vast majority of more taxing games is running at subnative resolution.

Edit: And I agree with dropping 3D too. It looks nice, but it is expensive. You could get a better resolution 2D than 3D screen for the same money.

...and the pricepoint will be very important !

Have people said more battery life? I can't barely enjoy my 3DS for three days without having to recharge it again :(

Lol there won't be a Vita successor to outperform it.

How would those things be a waste? Most people play handhelds on the go, so having a handheld that can access the internet wherever you go is literally staying modern. And not having bumpers when there is a viable way to implement them while keeping the same formfactor limits the potencial games the system can get and limits the synergy between it and it's home console counterpart, making it difficult to play the same game across platforms. That would be a waste. Instead you'd have a Vita situation where everything is almost cross playable. 

Take 3D away from my beloved handheld console next time Nintendo, it sucks.

I don't think it sucks. I just think it's a waste of resources. Devs already have to worry about making a game look good at a decent framerate. They shouldn't need to add 3D support the effort.