PS4K will be released in Sept 2017, 100% compatible with everything previouisly released on PS4, more poweful APU, more and faster RAM, at 399$. We will have two different SKUs, just choose one.

I wonder what would be the boost from PS4, if the new upgrade went with a custom r9 370x + Puma for the new apu...

If the thing is over 600$ it won't survive.

You can build a PC that can do 4K 30FPS Ultra settings or 4K 60FPS Medium settings for that amount.

PCPartPicker part list / Price breakdown by merchant

CPU: Intel Core i3-4170 3.7GHz Dual-Core Processor  ($114.78 @ OutletPC) 

Motherboard: Gigabyte GA-B85M-DS3H-A Micro ATX LGA1150 Motherboard  ($39.99 @ Newegg) 

Memory: Kingston HyperX Fury Black 8GB (1 x 8GB) DDR3-1866 Memory  ($33.88 @ OutletPC) 

Storage: Western Digital Caviar Blue 1TB 3.5" 7200RPM Internal Hard Drive  ($49.25 @ OutletPC) 

Video Card: Sapphire Radeon R9 390 8GB Nitro Video Card  ($299.99 @ Micro Center) 

Case: Thermaltake VL80001W2Z ATX Mid Tower Case  ($24.99 @ Micro Center) 

Power Supply: EVGA 750W 80+ Bronze Certified Semi-Modular ATX Power Supply  ($48.99 @ NCIX US) 

Total: $611.87

Prices include shipping, taxes, and discounts when available

Generated by PCPartPicker 2016-03-22 16:18 EDT-0400

I mostly want to see if Sony can pull something like this off, because these systems were not built to support something like this. Unless every old game is patched, all your old games will run exactly the same, and unless devs are morons, all new games will do is run better on the newer model. Which is really neat. And weird. Like how much more powerful is this thing going to be? There's no way I see it running 4K games unless they don't expect it to be a mass market product, but more niche like PSVR. Same with running all new PS4 games at 60fps. There's no way they're getting hardware that much more powerful than PS4 at an affordable price point with out taking a loss Sony hasn't been in the business of taking since this generation began.

I doubt Sony would ever let a game only be playable on a PS4.5, so no need to worry about that. It would be a PR nightmare. PS4 isn't a handheld. These aren't $200 replacements. PS4 was never marketed as an upgradable device. It wouldn't go well at all.

So mostly, I just want to see if it can succeed when they didn't lay the foundation at all for something like this.

PS4 will not be an upgradable device, we will just have a new SKU. I believe the new GPU could be based on a mid range AMD GPU which will be released in May/Jun 2016, using High-Bandwidth 3D Stacked Memory; Sony can have the new System at 399$ in Q4 2017, and easy capable of 4K ! This is hardware in a closed environment, it can do miracles !

"""The 2016 Polaris GPU architecture will enable a historic generational jump in performance per watt. For consumers, this means that Radeon GPUs could be at the heart of the most powerful thin and light notebooks and desktop gaming PCs we've ever seen, paving the way for unprecedented gaming and notebook performance in compelling small form-factors, thin and light computer designs."""

PS4K new GPU will most probably based on Polaris GPU architecture ! By Q4 2017 Sony can package all for 399$ ! I'm ready to place a bet with everybody.
http://www.dnaindia.com/scitech/report-amd-s-new-gpu-will-double-performance-per-watt-says-india-head-srinivas-m-2177877

Anyone who think that Sony can put out a 4K capable PS4 for under $400 has a fundamental misunderstanding of how companies make video game consoles and how those video game consoles make money.

Period.

Higher framerates, more details, better textures, better lighting, better effects, PC quality graphics in general. AMDs latest APU generation can bring 4K processing at relatively low cost, so a PS4K is very realistic.

http://www.eteknix.com/amd-raven-ridge-apus-will-combine-zen-polaris-hbm/

So what you want is a PC.

Why is it so hard?

Well said.

Neither M$ or $ony make any money on hardware sales (except accesoires).

Most of the times they make a lose.

Their profit comes from 

1) Third party game sales on the console.

2) First party game sales on the console.

3) Online subcription and other services (PS+/Xbox Live)

That's why exclusives don't make any sense.