I planing on getting a new monitor and I intend for it to be an HD monitor, and at some point I want to get a blu-ray player.
So my question is,
Does my Motherboard need to have HDMI outputs for the monitor to work as HD?
Or is a HD compatible GPU all I need?
Nope.. Just an HD compatible video card will work.
Typically video cards have DVI (Digital Video Interface) ports on them.
If you buy a monitor or a HDTV. Find out what ports are on the monitor or HDTV.
Typically monitors have DVI ports. HDTV's also have DVI ports most of the time... If the HDTV does not have a DVI port you can buy a cable which will convert DVI (from your computer's video card) to HDMI (on your HDTV). It's a cheap cable/adapter as long as you buy it from the right place. Most local stores are a ripoff, I reccomend you buy it online.
The monitor and output type needs to be HDCP compliant. DVI and HDMI are your options. Double check the specs on the mobo or card that you will use to output the video from, as well as your tv to ensure HDCP compliance.