I got this idea from a recent Neogaf? What do you want to see from the handheld variation of the NX, assuming there is one and it is independant from the home console variant?

What kind of hardware do you want to see? What features? What about the firmware and the OS? What price point should it start out at? What developer tools do you hope it runs? What kinds of games do you want it to recieve? What specs do you expect the hardware to run at?

I plan on giving a rundown of my expectatings in a separate post, but I'm interested in reading what you all want to see as well. I'm sure there will be some major differences of opinions but, you know, deal with it I guess. :D

I want it to be a portable version of the NX home console. I know it can't have the same power, but I'd like it to be able to play the same games, even if they have to be downscaled or get poorer textures. Keep the two screens, and leave the touchscreen be, these are really useful. 4-5 hours battery is a must. Use regular SD cards for memory, and please, don't make it digital only.

I want to see them keep the dual screens at least. Sure the hinges break on some (never had the problem myself) and the original 3DS developed scratch lines on the sides of the top screen due to resting on the bottom screen when closed (at first I was able to wipe it away but eventually it wouldn't wipe away). However, I like being able to close it and not worry about it getting scratched.  They just need to remember to put rest bumpers for top screen (New 3DS XL has bumpers but the original 3DS doesn't).

One 1080p oled screen.

I would like to see a handheld that can justify its own existence alongside smartphones. For example, I would like to see a highly compact handheld that can communicate with the gamer's smartphone and use the smartphone to perform graphical computations. It makes no sense to me why somebody would want to carry around a dedicated handheld with its own processor that is in every way weaker than the processor in their Iphone 6 which is sitting in their other pocket: it is redundant and a big part of why dedicated handhelds are becoming irrelevant, IMO.

1 screen.
Able to play same games as the NX home console, but at lower resolutions.

Would be happy with it being streamed, i like laying on my bed when playing. Did that with my Wii U sometimes.

1-720p screen;

2-proper Wii/Wii U ports;

3-price around 250$ if possible;

4-full crossbuy (for compatible games) with the NX home;

5-region free.

I want it to launch this yrar and finally replace the outdated 3DS.
I also don't want it to have the dame games as the next home console. Each system should have its unique games.

1. I want it to be backward compatible with all the eShop games I bought this gen. And I want to download them on my NX handheld for free or a very generous upgrade fee. The ability to play Smash Wii U, DK:TF, LBW, and my virtual console games I bought on the go would be an incredible incentive to buy it early just like how smartphone users love to upgrade their new phones at launch without worrying about losing their old apps.

2. I want the screens to be at least 720p for the first generation. Smart phones can already play games in HD, and in a few years be able to have 1080p screen. Nintendo needs to have HD screens as well. 

3. Get rid of friend codes. They probably will but since its still on the 3DS, its actually a valid request.

4. Miiverse 2.0 - now with Twitch/Youtube support: Sharing screenshots with Miiverse is great. But now that the competitors can stream their games on Twitch, so should NX handheld. Would be a great way for the consumers to shares these games easily with others. This means uploading the stream/game recording later to YouTube as well. Will also make life easier for Let's Players that Nintendo supports ie GameGrumps and Chuggaconroy.

5. Multitasking apps: 3DS already has some apps that can be multitasked but these are programmed to do so. You can switch to Netflix without closing your game for example. Mobile NX should be able to do this though. Which leads to the next point.

6. Sync your Nintendo NX to your smartphone and its apps: Just like how the Apple watch could sync with an iPhone text messaging app, I want an OPTION (chill guys) to have text notifications to pop up in my NX games and also the ability to respond to the text within the system seamlessly. If this can't happen, Twitter post notification or facebook messenger would suffice as well. Just make the system more social to digital age Nintendo! 

7. Easily "streamcast" your game onto the TV: This is simple. Do what does the Vita does with the PS4 or Vita TV but with the NX home version. But also allow it to do so with an Apple TV, Roku, or other TV streaming box (maybe PS4 or One as as well) with the NX streamcast app. 

The benefit of connecting to your NX home console instead of the others would mean you can use the NX controller instead of the handheld. And maybe you'll get more points as well.