the Switch's power falls somewhere between a Wii U and a PS4, so for Sony to make a PS4 portable they would need to either dial back on performance power which would only tick off devs and make them not support it, or they would need to make it expensive as hell which would tick off consumers and make them not buy it. also remember the Vita, which basically was a portable PS4 that people hated so much that Sony stopped making portable consoles entirely.
man... with all that in mind the Switch really seems a lot more planned out.
That's a looooot of a stretch. Vita isn't as powerful as a PS3, how can it be a "portable PS4"? What he meant was a portable version of PS4 that played all your PS4 games. That alone would give it a game library miles ahead of the Vita (and, currently, parsecs ahead of Switch). The only games the Vita shares with PS4 are some remasters and indies. Remasters aren't system selles and people don't care for indies (if you don't believe, just read the comment section of the monthly PS Plus free games at PS Blog).
Anyway, it could only be possible in 2 or 3 years, due to power/heat constraints. It would also be a problem for people who have a lot of physical media, since it would be digital only (PSP Go failed hard at this, but digital is stronger now). Unless they figured out a way to authorize people to access digital copies of their physical media, I think that would be a no-go. The fact that it would arrive when PS4 would be at the end of its life it's also a big problem.
However, it wouldn't need 3rd party support since it would already have a massive library of games. It coule be a killer concept if done right, a bunch of regular PS4 owners would get one to play games on-the-go. I think it would be more effective if we ended up forgetting gens and just using iterative console upgrades, but that won't happen anytime soon.