Elizabeth is correct! Many systems have (or will soon have) multiple HDMI compatable sources in use. My Cable Box and DVD player both have HDMI. Most TVs have a single HDMI port, so using the receiver as a switch allows you to use the superior HDMI output from both components.
Also, according to a review I read of the new Sony STR-DA7100ES, it upconverts analog signals to HDMI and uses its 12bit/216Mhz DAC to process the signal. Doing this would possibly allow you to only run one cable from your receiver to TV and simply connect all of your audio and video sources to the receiver. This would be especially nice for folks that have a wall mount TV or ceiling mount projector. You would only need to run one very thin cable through your wall to the TV, greatly simplifying installation.
Enjoy,
TIC
