HDMI and Component look exactly the same to me... I'm just saying >_>
P.S. I think the biggest reason for adding HDMI, is that very few TV's support 1080p through Component, and just a few have a VGA input... For many people, HDMI is their only options for 1080p on their 360.
-= Double Post =-
Also, i just read up, you can't watch HD DVD's at 1080p through component. Only VGA or HDMI... So, putting in HDMI gives people another option from VGA to play their HD DVD's at 1080p.