DisplayPort has been slow to be accepted as it adds costs to the video card and the monitors, over a VGA/DVI port. You want monitor prices to drop, yet add new features? Ok. See, that is one reason why it has been slow to be accepted as a standard. No one wants to pay for the feature. It does add a network controller to the video card and monitor as well.
DisplayPort will not work with regular monitors either. It requires a monitor which is not dependent on scan lines (LCD, Plasma, CMOS, OLED...). The only way a scan-line based monitor could work is if an internal decoder was added to decode the data packets back into scan lines for the display, thus adding more costs.
Quite frankly, the whole HDMI thing should have never happened. It was a very, very poor decision to implement HD content using scan-line technology. How many CRT based HD televisions do you see around these days?