Explain this comedy central Dave Chappelle joke to me.

This is one of those insignificant things that is driving me mad.

In the credits of a recent South Park episode we have, there is a voice-over saying that Comedy central aplogises for replacing Dave Chappelle with Somebody-else Chappelle (Edmund? Edward? Edna?) in the previous week’s show.

Not that I watch the show, it’s just annoying me that I have no idea what they are talking about.

A little help here please?