If the PS4k is as rumoured then I'll buy it. I won't like it (i.e. that I've been pressured into having to spend another £350 on an upgrade so soon), but I'll still bite if it's just a one-time mid-gen update for the purpose of Sony trying to push their VR platform and make it more competitive.
I see a lot of people speculating and talking as if whatever this is, it will set the tone for the direction of the industry from here on out. I'm not sure that it will. I'm not sure any consumer will be happy knowing that their expensive new console will be made obsolete before they even get the chance to play the next GTA or equivalent "long-lead dev time" blockbuster AAA game. And I think Sony understands this more than anyone.
I also think that the biggest potential benefit of more frequent generational shifts (e.g. 2-3 years), i.e. full forward compatibility, will be its biggest burden. As devs will need to have a cut off point at some stage, in terms of platforms they will have to target; otherwise they will end up spending far too much time QA testing for unnecessary legacy skus, which defeats the whole point of a console over a PC.
In which case I can see this going one of two ways:
1) PS4K will simply be a one-off mid-gen update and Sony will revert back to their normal 5-8 year generations starting from PS5 (but with full BC).
2) Sony will look to continue with their normal 5-8 year generations for a full 8-10x jump in performance from the last major shift; however they will drop mid-gen updates to the hardware alongside die-shrunk normal console revisions to play the same games at two distinctly different graphical configurations until the next major generational shift. So in this scenario, PS4 and PS4K will play all PS4 games, but only PS5 will play PS5 games together with BC PS4 titles.
I just can't see any benefit to either Sony, consumers or developers in shortening the full generational shifts to 3-4 years, especially when the biggest games take 3 yrs to make. This is the biggest distinction for me between consoles vs PC and phones. Who will buy a console knowing that all the games you're looking forward to will release optimised for newer HW in 1-2 years time. I think a lot of people will exit console gaming as a hobby if it becomes like PC.
Also, I think the argument that "you're not forced to upgrade" is a pretty intellectually dishonest one. It draws parallels between phones and PC where the markets are sufficiently different that such parallels are pretty useless.
With phones, you're tied into a contract anyway, which for most is usually between 18-24 months, so you couldn't upgrade annually even if you wanted to. Plus, because of your contract you upgrade because there's really no reason not to.
PCs again are different as PC gamers are not console gamers, and many console gamers are gamers BECAUSE of the lack of any pressure to upgrade more regularly in order to play the best games on their platform at the best performance possible. PC's are also modular and be upgraded component by component, which for some can alleviate some of the cost implications (i.e. if I only need to pay an additional £200 for a new GPU every two years, but can keep my motherboard and CPU for the next 3-4 years, then that's more palatable).
Making consoles like PCs however, suddenly creates psychological pressure on console gamers to upgrade more frequently, in a market that traditionally has been almost entirely predicated on a lack of need to update HW frequently. Suddenly, console gamers need to spend another $400-500 every three years and cannot just upgrade certain components in the box like on PC. So potentially the situation on consoles consoles becomes even worse than the situation on PC that console gamers were running away from in the first place. I'm gonna go ahead and say that not even Sony is dumb enough to go this route; hence either one of the two above options are really the only conceivable future for this.