i didn't know there were such a thing as downloadable disk!

to make a profit, i hope not. Sony has spoiled its fans for far to long.

It isn't that it would be bad for Sony to do it, in fact it would be good if any of the companies provided backwards compatibility to the PS2/XBox/Gamecube generation of consoles; but it really isn't practical.

Given a system that was 2 to 4 times the processing power of the PS3 and all the technical documentation for the PS2 a small team of qualified developers could produce an emulator in a couple of years that had a high level of compatibility with the PS2. Unfortunately, to get past being an "OK" emulator and being really good would require testing of a wide variety of games (hundreds of games), careful logging of inconsistencies between the emulator and the physical hardware, and lots of bug fixing; which would take a much larger team several years to complete.

After Sony or Microsoft spend tens of millions of dollars to do this, how many additional sales will they really get from this?

We'll be lucky to get PS3 compatibility. So I highly doubt PS2 compatibility. They probably see it as something very few people will use and they want to sell HD re-releases.

Completely agree.

But I hope they do include backwards functionality for PS3 games at the very least. It's always nice to have that bridge between consoles.

All PS2 games in PSN may work on PS4.

And the others PS2 games can be played via Gaikai.

no idea, but i see your point, which is wht i was getting at.

nope not gonna happen

Why are you people so quick to throw this out the window? The ps3 has ps1 emulation but not ps2 emulation so why is it absurd to think the ps4 would have support for ps1 and ps2 discs and not ps3?

Because sony abandoned their support of backwards compatibility.  Thats the only reason the ps3 has ps1 support, because that was a feature they initially pursued.  Why go through the effort to make software emulation for two gen old system?  That feature is going to cost a lot and not be a very big sytem seller.  It doesnt make sense for sony.

the only backwards compatibility that matters going into a new gen is the previous system because the hardware makers are trying to maintain loyalty.  

One solution I hope they do go with if proper PS2 b/c isn't a feature is disc recognition which allows for free streaming of games if you have the physical disc of the original PSX/2/3 game and the game is available through a streaming service. OTOH PS2 emulation should be as light on processing grunt on PS4 as PS1 emulation is on PS3. It's virtually zero cost for Sony to put PS2 emulation into PS4 so I hope they do this for the fans. PS3 emulation is pretty much off the table I think as is slapping a Cell into the PS4 (though they could experiment with a primo sku with a Cell inside charge whatever they like ($600) as long as they have a non-Cell sku for cheapness.