The ever-trenchant Steve Almond invokes Bill Hicks, Mark Twain, and George Carlin in his sharp critique of Jon Stewart and Stephen Colbert. I'm not sure he explicitly calls them corporate shills, but that's the gist:
Our lazy embrace of Stewart and Colbert is a testament to our own impoverished comic standards. We have come to accept coy mockery as genuine subversion and snarky mimesis as originality. It would be more accurate to describe our golden age of political comedy as the peak output of a lucrative corporate plantation whose chief export is a cheap and powerful opiate for progressive angst and rage.
Read the whole thing. And just 'cause: