Any idea if PS4 could upscalle 1440p to 4K ?

Was the standard for PS2 not 640x480 like all the other consoles of that generation?

EDIT:
240p for standard PS1 games
480i for high res PS1 and standard PS2
480p support for most ps2 games
720p for one or two games
1080i for GT4

Yes?

This is an awful explanation based on flawed resolution concepts. PS4 doesn't have the power to do much better than PS3 visuals at 1440p, never mind 2160p(4K). Also, PS3 also ran games at 1080p, and, funnily enough, the original Xbox ran one game at 1080i(a Matrix game) and a few at 720p(with PS2-comparable visuals), while GT4 also ran at 1080i on the PS2.

Pretty much what I came here to say.

I would say that 6th to 7th gen leap was bigger than 5th to 6th, since it marked the use o programmable GPUs vs. fixed function ones. Lightning on PS2 and PS1 is basically very similar, while PS3 has all the advantages of a shader capable GPU to render more realistic lightning. The jump on models and textures was bigger on PS1 to PS2, but lightning has the hability to grab much more attention than these two. Fixed function GPU games have terrible lightning compared to modern ones. We will probably see a massive leap with the 9th gen when they start to use ray tracing capable hardware and all 8th gen games will start to look really, really bad.

(I've used PS consoles as a reference, but the same can be said about Xbox 360 and Wii U compared with their fixed function GPU powered antecessors).

About the leap, is to soon to judge. When X360 came, people hurried to call it Xbox 1.5 and they were wrong. Resistance: FM looks like crap compared with Killzone 3 as GTA IV is horrible side by side with GTA V. So we can assume that Killzone Shadow Fall and Ryse will look like crap in 3 to 4 years compared with newer games.

For the PS2 resolution I just booted up an emulator and tested a few games. God of War 2 was 512X448 as well as most games. A few less intense games ran at 640X512. Also googled it and got similar results. I can check GT4 if you want.

Well if u talk leap and 3d it has to be 3ds

Well if the tv is 4k, you're going to see a 4k image.

Nonsense. The PS2 was the same price as the PS1 and was a MUCH bigger leap than we are getting now. 

my bad, what i mean is its cheaper than PS3 launch price, so don't expect too much leap over PS3...