Last week when I was trying to watch the Daily Show, I could no longer find Comedy Central in my saved channel guide. As it turned out, this wasn't a bad thing: Comedy Central HD was just added to the DirecTV lineup, so the number had changed.
This is good news. But from what I could tell, much of the content is broadcast in pillarboxed 4:3? So while it's not widescreen, at least it's clear and sharp.
South Park will be broadcast in HD as well on the 13th season. Link ibid.