It's a dirty job, but somebody's got to tell you that the Discovery Channel is canceling "Dirty Jobs," "a forerunner to the genre of weird-workplace reality television that now flourishes on cable," after nine years on air, according to Brian Stelter. Good quote from the show's host -- featuring "exploding toilets...and feces from every species" -- on this post. This is the second long-running Discovery show to get the ax this month. "American Choppers," which premiered in 2002, was canceled last week.