I'm looking forward to HD. So far, the only 'programme' I've watched that benefited has been David Attenborough documentaries, and one or two films on BluRay (though most BluRay films add a lot of noise to make up for the fact that HD doesn't add ANYTHING to the picture quality).
F1 will benefit from it. I'm annoyed I won't have HD where I live until the end of the season at the earliest. And my TV is only a second hand 720p one, but will still be nice (although as the broadcast will be in 1080i I'll be okay, as I think my TV can do that natively too).
But I have NEVER once thought the picture quality in 'SD' wasn't good enough to see the details I've needed to see. Hell, even in footage from the 60s and 70s there is enough detail to see everything vaguely important.