The Daily Show was originally a well-mixed but Frankenstein hybrid of news parody, news magazine parody and talk show. As the show has focused it’s targets on news media and politics, the interview topics have been more serious. The casual couch and the celebrity guests it was meant to feature have become to stick out a bit. Maybe the couch worked at first to be a place where politicians could let their hair down, but as the interviews have turned to be more serious in topic (and sharper in satiric bite), The Daily Show has had less reason to repeat the late night talk show mold.
By having everything delivered from the desk, The Daily Show fully imitates the news shows it satirizes. Much of the show is a brazen critique of news media and by turning the set into something you would see on CNN, Fox News or MSNBC, you make it clear who your targets are. You don’t see guests on those channels lounging on couches talking about world affairs. When you’re attacking something by using its voice and mannerisms, it’s vital to get the imitation as close to perfect as possible. The new set does exactly that, making the jokes that much more pointed.
As for the three huge flat panel monitors… eh.
Updated: This LA Times article also makes a good point about how going sans couch may make Stewart a more focused and targeted interviewer. Example being the conversation with Bernard Goldberg (one of the most talked about TDS interviews in recent memory).