There won't be such thing as "the next Wii" as long as the tablet and mobile games have most casuals ocuppied. And even if it becomes popular thanks to the VR set, it will be too expensive for casuals to care about.

The Wii sold by grabbing a casual market by demonstrating an incredible novel technology that wowed them.

So in simpe terms the question is: (Morpheus Mark 2 = Wii-mote and Nunchuck) = ?

Absolutely not!
PS5 will be like PS4, built around being a great core gaming device, made for developers and gamers alike.
It'll of course have a faster processor, like another SOC, with High Bandwidth Memory, 8GBs+ running at over 2TB/s for VRAM, built on die and the system will have Universal Memory, basically a multi-terabyte SSD that functions as both RAM and your HDD, giving developers at least a dedicated 200GBs of dedicated memory for games, running at a few hundred GB/s.

If Morpheus takes off then I would expect Sony to basically bring out an updated version, that can handle higher frame rates, with a faster refresh rate on the headset's panels and also a higher resolution, probably with better latency, but that's about it.

Sony has the perfect formula for a successful future in the console space, there's no reason why they would risk that by trying to mess with what actually works.

No. Nothing will be like the Wii. It was a cultural phenomenon. There are already too many other companies making VR headsets. The only one that was really out with motion controls when it launched was Wii. Plus they had the games for it at launch.

I think psNow will be PS5 in the future. Easy access and Sony finally gets full control of all aspects of the system, because its streaming.

I just find it interesting that Sony are lately so obsessed with pursuing the 'cinematic' gamer... but it makes a lot more sense if Sony as a company suspect that the Morpheus could become an avenue that both its film and game companies would benefit massively from. Ofcourse that means expanding their audience to be a larger group than just dedicated gamers and 'stolen' film buffs. Whether its their incredible work with "The Last of Us" or their most recent project "The Order" they've clearly shown SOME interest in blending those two media. From my brief experience with Occulus I can totally imagine that being the best path for the technology. 

Doing so effectively would likely require a price-tag maxing out at roughly $200. Ofcourse they could start at maximum of $300 ($250 would be best) if they were confident in their ability to cut it down from there within the first year. I mean the used the PS3 to push Blu-Ray and that worked out for them in the larger sense.

A platform going completely streaming based is reliant on the internet being 100% reliable, but that's never going to happen until each household has a system that can't malfunction.

There will always be physical hardware, that handles the local processing of games. No doubt the cloud will be a feature of 9th gen and consoles that come out beyond that, but it will never take over while the internet lacks reliability. There's also the matter of costs, if people aren't willing to pay for a regular subscription model, on top of PS Plus or XBL then there's very little reason to go all out on the streaming side of the platform.

Going for the full streaming based model is pointless when developers can already make huge worlds on the current generation of consoles and PC. We have games like No Man's Sky and WiLD coming out this year, one offers an environment the size of Europe, the other procedurally generates an ever expanding galaxy worth of planets to explore, the next generation of consoles will be able to take that even further, hell this generation will as well, because over time developers will optimize their code on current systems to get more out of them, the same things will happen next gen, basically pushing games several orders of maginitude further than what we have this generation.

Cloud based consoles would also have issues of latency for the user, so any kind of seamless experience won't compete with what will be possible on local hardware.

Being obsessed would mean that basically all of Sony's focus on gaming would be towards games like The Order, but there's simply no proof of that, I mean this year we only have Until Dawn and The Order 1886, even Uncharted isn't what you'd call an all out cinematic title, it's no doubt packed with gameplay, like past Uncharteds and TLOU, every other game coming exclusively to PS4 this year is very gameplay focused.

Sony's developers using cutscenes and QTE isn't a sign of anything other than it having it's uses in some games.

This generation has shown that Playstation isn't about focusing on gimicks, rather those are sold separately, past generations showed exactly the same thing.

Same goes for using streaming for games like in PS Now, risking everything on that, when physical hardware has worked fine for every past console generation and the internet lacks the reliability of physical hardware you don't focus on only using that, because that would be annoying for your potential install base.

It's way too early to say. Maybe it will, or maybe it won't. We'll have to see if the PS5, or even anything else could sell at Wii levels.

Knowing Sony, it's going to be the same thing essentially - like this gen, PS4 is a simple upgrade to the PS3 W/O PS Move.

Well, by that logic, the next 'Wii' or in other words the next 'mass market fad' could be the Morpheus itself.  So, not so much the PS5, but rather the PS4 with VR or the OR.   Also, believe me when I say that unless Facebook finds some way to leverage their social network to get folks on board with VR; the PS4 will be the go to platofm for the tech.   And the Xbox One's Halo Lens is an interesting idea, but see it being used for applications outsided of gaming.  THe full immersion of VR/Morpheus has no equal in Agumented Reality.