Sorry for being a decade too early, this is what I think will be the specs of the PS5:
56-64GB RAM 16x4 GiB GDDR6 memory chips (set to be introduced within 2-3 years, GDDR5 was introduced in 2008)
4K gaming will be possible, but QHD (2560x1440)/WQXGA+ (3200x1800) 16:9 resolutions will also be common in individual cases depending on the Virtual Reality support and if 4K proves too taxing. VR games will be 1440 or 1800p, 90-120fps.
~12GB RAM will be reserved for the OS, the footprint will decrease gradually over time.
Release: November 2019, 6 years after the launch of PS4. It might come out 2 years after Nintendo's next and 1 year after Xbone successor if MS wants to release a year earlier again if they're beaten badly this gen.
Motivation behind my estimates:
+10-12TFLOP: PS3 was ~300-400, PS4 is 1.95TFLOP so 5x increase, ofcourse AMD is bringing out 295X2 which is 11.5TFLOP, the card costs 1.5k dollars, but it will take more than 5 years before we see such a beast of a card become the mainstream standard (200-250 bucks) which is the tier of cards next gen consoles will feature. But the 295X2 will be ancient in terms of technology and features by 2019, by then the cards will be on newer memory and GCN version etc.
RAM: basically an increase of ~8x, this is half of what RAM increases of previous generations: PS2 32MB, PS3 512, PS4 8GB, I think a 16x increase(128GB) is a bit too much this time around.
12-16CPU cores: cpu's will have more cores to handle more tasks, AMD and Intel already provide cpu's with that many cores for server solutions.
Firsts for many in the industry:
-First time real ray tracing in games
-VR becoming mainstream, bundles with PS5, 4K OLED VR headset affordable
-4K gaming becoming mainstream
-CGI like graphics feasible by mid gen thanks to enormous amount of horse power and memory
>32GB system ram+>16GB vram common place in the average high end gamer's rig.
What do you think?