The definition of an HD channel?

This has become the year of new HD channels and while we can't get enough HD, Mark Cuban brings up a good point on his blog. There are lots of new HD channels, but not so much actual HD. Of course this is nothing new, even the earliest so-called HD channels showed mostly SD material, and even today most HD network show as much SD as HD. There are of course a few 24x7 HD networks, but most of them are inundated with reruns. This persistent problem seems to be getting worse as we'll soon have one HD network that isn't HD at all, and others that don't plan to do much HD in their first year. Don't get us wrong we're not complaining, but we think now might be a good time for the industry to come up with a definition of an HD channel.