It wouldnt be that bad, Steam were going to do it but scrapped it most likely due to costs. I would pressume thats why Sony didnt go with it.

exactly.. for reference this has a screen diagonal of 2.14" and rez of 480x360

And the PS4 touchpad, and only talking about the square part not including the curved part that on top has diagonal of 2.34". Bigger than what you have in a BB bold, theough the apsect ratio is differnt (bold is more square and PS4Tp is more wide). If you aske me, not making that a 480x360 rez color screen or something like that is a major missed opportunity by sony. They could have even completely done away with teh share and menu buttons and let those just be zones on an even bigger touchpad/screen.

Then again the controller would probably have cost $100 on its own. 

Pretty sure touch screen was implemented to emulate a Mouse for PC. Seeing that they're porting so many free to play games I wouldn't be shocked to start seeing some more MMORPGS down the line using the touch pad as a mouse.

Didn't MM say themselves they had a hard time porting over their game to the PS4 due to the physical limitations?

I doubt this is the case.

I like the touch pad simply because it gives me a larger area to press, instead of trying to locate a small options/start/select button. Like in TLOUR for crafting upgrades and similar, or in Infamous to swipe open the doors etc.

Not that it is essential, but it certainly doesn't get in the way of normal gamepad usage...

Doubt it, i think it was added as it simply because it offers more input opportunities.

You bring up a very good argument. That might have been one of the big reasons why they added a touchscreen on the DS4.