Mitt Romney, Stephen Colbert Mitt Romney, Stephen Colbert

Stephen Colbert has promised to have high-profile guests when he takes over as host of Late Show next month, and he's already getting a head start.

In one new promo for the Colbert-led Late Show, former presidential candidate Mitt Romney makes a cameo appearance. Of course, Colbert - in character as his dim-witted political pundit - has no idea it's really the former Massachusetts governor. "Wow, you do a great Mitt Romney," Colbert gushes.

In another promo, Colbert shows off a hot new back-to-school accessory: a Charlie Rose Trapper Keeper.

The former host of The Colbert Report was named as David Letterman's successor last year. The Late Show with Stephen Colbert will premiere on Sept. 8 on CBS. Check out the promos below - will you watch?

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(Full disclosure: is owned by CBS.)