But I can't see Williams falling from the top spot. He is too good -- and popular.
It may be too soon to anoint Williams as America's Most Trusted person. But it has become clear that the "NBC Nightly News" anchor has established himself as the Walter Cronkite of the 21st century.
Williams towers above the competition and has regularly won in the hotly contested ratings war for 6:30 p.m. Plus, he helped to hold NBC News together through periods of transition.
Perhaps his signature accomplishment has been to re-define what a news anchor can be, by showing a humorous side away from the 6:30 glare. Much has been made by commentators of the immense challenge posed to journalists during the digital and 24/7 news age. But Williams has remained relevant.
And yet ...
Williams may be the most under-appreciated television journalist of his time -- though NBC surely recognizes his accomplishments. Williams is so steady that he isn't likely to figure in controversies, like Dan Rather. He has not experienced the drama of Bob Woodruff of ABC, who nearly died while covering a story in a war zone.
Speaking of generating headlines, he isn't as provocative as Katie Couric, either. Couric of CBS has received splashier headlines than Williams because of the historical significance of her anchoring the evening news and a highly publicized move from NBC's "Today" show.
In a 2006 profile I wrote that it's easy to take Williams's steadiness for blandness on occasion, but that would be a mistake.
I'll stand by that today.
Perspective and calm
Still, Williams, 51, has put his stamp on the job since he succeeded Tom Brokaw in 2004, as Williams elevated himself to be his generation's version of Cronkite.
Where Cronkite's greatest skill was his ability to calm viewers during the tumultuous times of the Vietnam War and the Watergate scandal, Williams does well at putting the news in perspective.
The role of network anchor is sure to receive fresh scrutiny as we move closer to a possible announcement of a between CBS News and CNN. CBS has been stuck in third-place for many years.
If CBS's top management had its way, and didn't have to worry about the public-relations fallout, it might secretly want to scrap the traditional 6:30 p.m. evening news format altogether.
Recently, ABC (NYSE:DIS) promoted Diane Sawyer from "Good Morning America" to anchor its evening-news program. Still, Williams rolls on, virtually untouched by the competition.
Williams deserves credit on many fronts. First, following Brokaw, who had thrived and trumped his rivals in the ratings, was a daunting act to follow. Williams also helped NBC News survive as an institution after the death of the long-time "Meet the Press" moderator Tim Russert two years ago. (Brokaw did his part, too, by filling in on "Meet the Press" for a few months.)
When Williams began in the anchor chair, I wasn't terribly impressed with his work. He sounded stiff and pretentious. He seemed to me to be burdened by the weight of succeeding Brokaw -- and, putting it bluntly, possibly in over his head. He reminded me of a pitcher who kept struggling on the mound and invariably walked the bases full.
I never doubted Williams' innate sense of self-confidence. After all, nobody rises to that lofty professional level without having a hunger for great success and recognition. It seemed, however, that Williams wasn't quite being himself.
Finally, Williams loosened up. He became known for his funny appearances on "The Daily Show" with Jon Stewart. He appeared on the "Weekend Update" segment of "Saturday Night Live," subsequently hosted the show itself one week and enlivened "30 Rock."
Those were shrewd career moves -- though they might have struck some as being a tad undignified. (Would Cronkite have rushed to go on "The Smothers Brothers Comedy Hour" in the late 1960s? Not so much.)
By showing his informal side, Williams broadened the persona of a news anchor. He could show that he wasn't bound to the anchor seat. He could present a variety of styles to viewers. Williams helped to demystify the evening-news anchor.
Williams carried it off because he is such a witty and winning speaker. Several years ago, Williams came to Time Magazine's (NYSE:TWX) annual lunch to discuss the candidates for the magazine's Person of the Year award. He talked about the merits of honoring bloggers.
Williams dismissed bloggers by saying: "God love them. (Bloggers) are anxious to share with us their choice of a tuna sandwich for lunch."
It's likely that Williams will never replace Cronkite in historians' hearts and minds. The unofficial designation of Most Trusted may be out of his reach.
So, Williams will have to settle for the title of Most Reliable.