If you can't tell the difference in HD quality and you have all the HD stuff, watch an MLS soccer game on ESPN2HD this year and then watch another one two days later on Fox Soccer Channel in SD.
No frickin' comparison.
There is also no comparison between BD movies played back on my PS3, and ANY of the content available from cable or satellite. The effort being made by the content providers is laughable. The larger your display, the easier it is to see the difference.
I project my ATT&T U-Verse, PS3, and iMac onto a 110" screen. U-Verse has a lot of room for improvement.