( CNN ) -- Only a week after David Letterman surprised viewers with his on-air vow to step down from late-night TV in 2015 , CBS moved with stunning speed to anoint and announce his replacement : Comedy Central 's Stephen Colbert . Colbert , who has hosted `` The Colbert Report '' since 2005 in the tongue-in-cheek character of a pompous political conservative , was quoted by Bill Carter of The New York Times as saying he would be appearing on CBS as himself , not his comic alter ego . Signing the quotable and often controversial Colbert , with his legion of `` Colbert Nation '' social media fans , clearly is a gain for CBS . But for fans of Colbert , and for Colbert himself , it 's much more of a risk . The CBS thought process is easy to deconstruct . Either the network was going to give the `` Late Show '' slot , when it opened , to Craig Ferguson , who has toiled loyally in the time slot following it for as long as `` The Colbert Report '' has been on cable , or to someone else . Ferguson will be 52 next month -- but Colbert , also next month , will turn 50 , compared with ABC 's Jimmy Kimmel and NBC 's Jimmy Fallon , who later this year will turn 46 and 40 , respectively . So the issue is n't so much age as , perhaps , buzz , with Colbert 's social media savvy giving him the edge . The question now becomes , though , how much edge can Colbert bring to CBS , especially without the once-removed antagonistic persona of his Comedy Central blowhard ? Bill Maher offended too many people when he was on a late-night broadcast show , `` Politically Incorrect , '' but the same act has thrived , and taken root , on cable 's HBO . Going in the opposite direction , how many edges must Colbert sand off to maintain or increase a loyal audience on CBS ? In character on `` The Colbert Report , '' Colbert is such a smart and funny interviewer that , even out of character , he should prove much better in that department than either of the late-night Jimmys . But unless he generates the same sort of viral videos , most of them musical , that Kimmel and Fallon have presented so successfully , Colbert may struggle to compete . Colbert is a very strong singer -- even Stephen Sondheim thinks so , and cast him in a concert version of `` Company '' -- so he could do that sort of thing . But does he even want to ? And will his Comedy Central audience even follow him to CBS ? Success in one arena does n't necessarily translate after a move to another venue . Just ask Oprah . Personally , I like what CBS is gaining here . The potential for Colbert , who 's such a phenomenal workhorse on his current show , to craft a new show for CBS is enticing , and the unknown factor of what he will bring to the program as himself should generate plenty of publicity . For CBS , the move makes sense . But for Colbert , the transplant could be tricky . Young viewers -- and he certainly has them -- are fickle , and those who watch him on the more subversive Comedy Central may not be inclined to switch to the less cool CBS just to follow him . And many , like myself , will miss `` The Colbert Report '' greatly . There 's no show on TV quite like it . ( The logical replacement for Colbert , thinking one more step ahead , would be former `` Daily Show '' correspondent John Oliver , but his new current events comedy show begins later this month on HBO -- so he may or may not be available when the slot opens next year . ) And in addition to losing `` The Colbert Report , '' viewers also are all but certain to lose `` The Late Late Show With Craig Ferguson '' when his current contract expires -- so that 's two entertaining late-night programs that we 're losing , just to get a replacement for Letterman . Whether it all ends up being a good exchange for viewers depends on those other replacements , and how good Colbert ends up being at playing a formerly unseen and untested role : himself . My guess is that , as himself , Stephen Colbert will produce and star in a very good show indeed . But with the show being on CBS in the multimedia climate of 2015 , my worry is whether that will prove to be enough .
David Bianculli : Colbert slated to replace Letterman ; great for CBS , risky for Colbert . He says Colbert brings new late-night essentials : social media savvy , buzz . But Colbert could lose edge when he drops persona ; will fans follow him , he asks ? The Associated Press contributed to this report.