[yes, I know that some of you are gonna laugh ._. ]
DISCLAIMER: This thread will describe what to me is the perfect NX console scenario while taking into account what Nintendo said so far (So no 2019 release date or something like that), and talk about the next handheld will remain minimal. Also, there's a LOT of hopefulness here, as this is the perfect scenario. That is all.
I'm taking into account the Handheld/Console "brother" thing Iwata talked about, as well as Miyamoto's recent quotes, and other things.
Release time: So the perfect release time (based on current Nintendo quotes and expectations) would be Late 2017, with the reveal being at next E3 and E3 2017 would show what is pretty much the finalized design.
Uniqueness: I doubt Nintendo will release a standard console and as we've seen from the WiiU they shouldn't release a console that is "too unique", so my suggestion would be something "semi-standard", i.e. pretty much a standard console but with a controller that looks like a Gamepad-Standard controller hybrid.
The controller shouldn't be too costly to produce as to not make the console too expensive, or in this case too weak (both ala WiiU).
Power: Powerwise I'm hoping this will be as powerful as it can be. Nintendo won't make something too expensive (i.e. 500$) but they've proven that they're not against being a bit more expensive than usual (WiiU at 350$), so with that in mind if they go the standard component route which is prefered, they'd be able to get some pretty cheap vendors and would be able to make something pretty good for the price in the power department. Being released 4 years after the PS4/Xbone, the console would be quite a bit more powerful than those 2 if it's standard. I'm expecting the Xbox2/PS5 to release in late 2019, and with the NX being semi-standard and being released only 2 years before, there'd be a power difference but not even close to the current WiiU - PS4/Xbone power difference. With that in mind, the NX would be able to recieve the best looking console 3rd party ports compared to the PS4/Xbone for the 2 years they'd compete, and when the PS5/Xbox 2 release they'd be stronger but not to the point that 3rd parties couldn't port their games for cheap, so while the NX would be weaker than the other 9th gen consoles, it'll still be in the same ballpark of power, which directly matches Miyamoto's recent quotes about power.
3rd Parties: Now this is the real kicker. As we've seen from recent times, 3rd parties would pursue anything that'd give them bigger profits. And if the NX will release with a standard architecture, the porting costs would go down so much that even low sales would get the 3rd parties profits. Even in the GC era having a standard console (not arch-wise though, but there was no standard back then), 3rd parties did port stuff even though they got low sales, because they made some money some of the time. With this "perfect" NX scenario, they'd port stuff because making money would be gauranteed for the most part, and that'll lead to more people getting 3rd party games on Nintendo's platform (The fact that the games will look a lot better than the competing Xbone/PS4 for 2 years will greatly help), and that'll lead to more 3rd party incentives, and more 3rd party games, and the rest will be history. Of course, this isn't the likeliest of things to happen given Nintendo's recent past, but they have the potential to pull it off if they play their cards right.
Architecture: This is something very important too, Nintendo has said that the NX (future platform) would absorb the WiiU architecture, but I hope that this doesn't mean that it'll be PowerPC as that would handicap the NX in extreme ways. What they need to do is got the standard x86 route, or even ARM (but x86 would be more prefered as it's more "standard" and will co-allign with the other consoles.) either way it'd likely be something the handheld will be able to match as they seem to be planning similar architectures for both platforms. Either the console will ride the handheld (NX console will be ARM), or the other way around (Handheld would somehow be x86. Let's hope intel does something about that, lol). But similar development for the console and handheld could just be similar developing software, but I'm not betting on that. As long as it's not something like PowerPC, it's all good. But again, x86 is prefered.
Games: I've talked 3rd party, but 1st party-wise they need to expand their studios a bit as whatever graphical levels will be the norm then will undoubtably spread them thin, seeing as they're doing a terrible job at even 720p development right now. While I'm hoping the 3rd party situation will improve, They'll definitely have to push themselves the most when the console's in its first years, they'd have to support it pretty good. A lot of people (most of which say that NX will launch in 2016) say that Zelda U will be cross gen between WiiU and NX, but I doubt that. I think that ZeldaU will launch on WiiU in 2016, but a remastered version at a much higher resolution and at 60fps would release with the NX AT LAUNCH which might not be Twilight Princess Wii epic, but epic nontheless. Another thing they could do would be to re-use ZeldaU's HD assets to make a new Zelda NX using ZeldaU's assets (ala OoT and Majora's Mask), which would release in the post-launch period, or holiday 2018 at most. Whatever they do, they'd need to perfect and not slack off/underestimate things like what happened with the WiiU.
In the end, we should keep in mind that this is Nintendo we're talking about. Either they'll do something amazing and follow all this stuff, or they'll release a console that's weaker than the PS4 ._. Only time can tell.
That's all for now. Do let me know what you think, and if you have any suggestions for better ideas, or disagree with any of these points being in a "perfect scenario", post about it :P