HDCP is electronic copy protection to watch copywrited HD video (like 'The Hangover' Blu-Ray). Both the source and the display must be HDCP compliant to watch the movie at full resolution. The source is either a Blu-Ray Player or a video card that support HDCP thru the DVI port or HDMI port.
HD video is 1920 x 1080 (aka 1080p) or 16:9 aspect; a 2.35:1 aspect movie like Batman: The Dark Knight will have black horizontal bars both top and bottom of the screen. The Asus you picked out is 1600 x 900. It is a 16:9 aspect monitor, but the HD video resolution will be shrunk down to fit the screen. This results in a slight degradation to video quality.