VIDEO: Joan Rivers, Tracy Morgan Weigh In on Colbert/Letterman News

On last night's WATCH WHAT HAPPENS LIVE, a viewer called in to ask guests Joan Rivers and Tracy Morgan what they think about Stephen Colbert replacing David Letterman.

"It'll be interesting because we don't really know who he is," said Rivers, referring to the fact that Colbert plays a character on his current late night show. "But he's very smart!" Check out the clip below!

'Watch What Happens: Live' is Bravo's late-night, interactive talk show that features guests from the WORLD of entertainment, politics, and pop culture. Hosted by Andy Cohen, the series includes lively debates on everything from fashion, the latest on everyone's favorite Bravolebrities, and what celebrity is making headlines that week.

Past guests who have joined Cohen in the Bravo Clubhouse include Sarah Jessica Parker, Tina Fey, Iman, Liam Neeson, Kelly Ripa, Jimmy Fallon, Anderson Cooper, Molly Shannon, Matthew Broderick, and Lance Bass.