By Ken Tucker
Updated January 09, 2012 at 03:12 PM EST

Warning to guests appearing on the new CBS This Morning: The “greenroom” — the traditional name for the backstage place where guests wait before appearing on camera — is a “glass room” on the new set. Don’t get caught chomping down on a bagel just because Charlie Rose is talking to Newt Gingrich — the camera may catch you in mid-bite! During the 8 a.m. hour of the CBS This Morning premiere, the camera panned away from the new set’s combination of high-tech roundtable and old-fashioned brick-and-bookshelf backdrop to reveal a transparent greenroom where the obligatory table with coffee, sweets, and fruit plate plus sofas were joined by upcoming guests Julianna Margulies and Melissa Etheridge chatting with each other. In my occasional visits to network greenrooms, the atmosphere is hushed, with guests maintaining wary distance, silently contemplating their upcoming talking-points; we’ll see how long the bigger celebs put up with an exposed view.

Mixed message set aside, the newly christened CBS news show made a lively debut. Anchor-hosts Charlie Rose, Gayle King, and Erica Hill maintained a brisk pace and showed some degree of chemistry. CBS News kept the right person from the earlier incarnation of this broadcast: Hill handles both hard news and light features with deft skill, and engaged in easy small talk with Rose and King. On the opening edition, This Morning played to the newbies’ incoming strengths: Rose handled the political stories, such as an interview with Gingrich (who shamelessly played up to Charlie by saying he was running “a Charlie Rose-style campaign, ideas-driven”), while King fielded the pop-culture stuff, such as a report on Kate Middleton. Which is just as well, because I never again want to hear Charlie have to handle an item, as he did this morning, about Beyonce and Jay-Z’s baby, during which he said, “It’s a huge Twitter topic that Twitter friends have been tweeting.” Memo to producers: Save our dear Charlie from social-media updates!

The best thing about the show, however, is that most of the time, all three hosts seemed perfectly at ease and confident negotiating the various roles required on a morning show. I’d encourage more interaction among them, and the show clearly needs to add a supporting character in the tradition of Al Roker to deliver both the weather and a few zingers for the three hosts to chuckle over.

The challenge, of course, is to become a show that can compete against The Today Show and Good Morning America (as well as cable’s Fox and Friends and Morning Joe). I’m hoping that glass roundtable (a subconscious visual reference to Rose’s round wooden PBS discussion table?) becomes a place where the hosts and their guests engage in spirited debate. In morning TV, energy counts as much as ideas do.

Twitter: @kentucker