I hope its not the case but we will see. They have VR, and home console to support. A third pillar in portable system may be too much on the plate unless they really want to get back in the game.

The reason why the Vita failed is because Sony gave up on it after it started falling way behind the 3DS sales. To the point it was barely mentioned at conventions. I played a couple games early in its life (Uncharted, PS:All-Stars, Gravity Rush, etc.) and got both the Slim and original Vita but after a certain period gave up on the system and sold it. 

I will probably get the PSP2 or whatever its going to be called IF one truly exists only after seeing what the game lineup would look like. But if they fail to support the console again I'm not buying another Sony portable.

1. Yep

2. Still can't prove it, and we're not here to speculate. 

As platforms, Sony's worst still did better than two of Nintendo's worst.

nope. That's the biggest failure since the virtual boy

https://en.wikipedia.org/wiki/PlayStation_TV

AMD has been showing Zen 2 mid-late 2018 at 7nm. Whether they will hit that timeframe or not is hard to say.

PS could shoot for a handheld at that point, but do they want to is the question? Truthfully, I think keeping XB at bay is more important to PS than competing with NIN. If PS doesn't put enough effort into the handheld then it will just fail again, so whats the point? If they put too much focus on the handheld, then that could hurt PS4/PS5, and let XB back into the ring.

Now if PS is feeling cocky again and thinks it has enough of a lead over XB that they can be "foolish" and not regret it, then they may very well launch a handheld. There is also the fact that Switch is supposed to be a conosle first, and if PS feels that Switch starts cutting into its console sales too much, they may launch a handheld/hybrid competitor to simply keep/get people in the PS ecosystem. If they are going to launch a Switch competitor, I highly doubt it will be half assed. 

Then there's also the big what if, of will XB ever launch a handheld, since they made it crystal clear they've been messing around with the idea for some time now but just havent followed through. This would almost force PS to make a competitor. However, with VR, do PS or XB need to worry about handheld at all?

What's the right answer? I dunno. There's too many variables. I would guess based on PS4 and Pro, that PS has clearly learned some lessons and knows to approach things much more carefully this time around.

Yeah, still another sku, not a platform in its own right. Here, I'll spell it out for you:

The Virtual Boy had titles and an operating system made for it.

The Wii U had titles and an operating system made for it.

The Vita had titles and an operating system made for it.

The PlayStation TV used a Vita Operating​ System and played titles available on the Vita.

The PSPgo used a PSP operating system (customized XMB) and played titles available on the PSP.

The Virtual Boy, Wii U, and Vita are failed platforms.

The PSTV and PSPgo are failed SKUs.

0% Unless if the PS5 is a direct copy of the Switch then I don't see Sony ever making another handheld.

By the end of this year, Sony will have to shift focus to Playstation 5 development anyway, and that's always going to be the killer for any PS portable ... it's always going to have to be the little step-brother who's never as loved by his parents (Sony) as the PS5 will be.

Even if PS5 launches in 2020, the bulk of the R&D, planning and all that has to start now, system's don't just magically spring out of thin air.

So given that, where really does a Sony portable fit here? Given how Switch is selling, Nintendo will be easily 20+ million ahead as well.

There's so much wrong in your post I don't know where to begin. You act like making a super efficent 7nm PS4 APU is just arbitrary, like they haven't made one yet because they haven't felt like it. The techology isn't there. It's nowhere close to being there, and it won't be for years and years and years and years. Even if we did, the poor yields such a size for that processor would undoubtedly generate would make this processor super expensive to produce and extremely difficult to mass produce in huge volumes. It really isn't there.

Cerny's decision to go X86 has nothing to do with "scalability" (which again, is a complete non-starter considering how consoles maintain their performance advantage over equivalent PC hardware by abandoning scalability). They switched to X86 because it's a widely known arcitecture that's much easier to optimize and maximize hardware performance. The game developers wanted it because they felt it would allow them the easiest pathway to get the most out of the arcitecture. That's it. Cerny was hesitant about choosing it until the developers changed his mind. There's absolutely nothing about the X86 that makes it more "scalable" that other processor arcitectures. Where are you getting this from?

As for SSDs, what does that have to do with anything? Seriously. What does this have to do with mobile processing at all. Think you're going to get say a 1TB SSD at an affordable size? Just take a look at M.2 form factor SSDs at that size? I mean they're *only* $300 retail, and they really need to be like $40-$50 retail like current PS4 hard drives are in order for that to be feasible in a handheld, and that is not happening in the next 2-3 years.

Sony won't do what your suggesting because it's completely non-sensical. I know you're super convinced just how right you are, but honestly man I have no idea why. I mean you sincerely argued that Sony should be putting the PS4 OS on mobile phones. You really, really need to do more research, and get more technical knowledge about this stuff.

What rumour? Is there an "official" rumour, or is the rumour just people making threads like this based on nothing?

It could happen if sony makes a hybrid console like the switch