Yep, you and I have been about the only members that have noticed and written about it...Comedy Central on Dish is still central channel audio only even though all of their content is produced and transmitted in 5.1. Dish is either messing with the audio or are being given a feed that nobody else is and is too inattentive to notice.
Here's the thread:
Comedy Central not broadcasting in 5.1 or 2.0 lately..?