The big questions now are whether this is a one-time surge and, if not, what exactly is driving the shift in the usually stable nightly news ratings.

For the week ended Feb. 11, the most recent available, “World News” averaged 9.7 million total viewers, 180,000 ahead of “Nightly News” for its best delivery since February 2005 and first victory over NBC since July.

“World News” now ranks No. 1 during the February sweeps in both total viewers and adults 25-54, through the first 10 days of the ratings period.

Perhaps most important, “World News” was the only telecast to see gains over the same week last year in total viewers, up 6 percent. “Nightly News” and CBS’s “Evening News with Katie Couric” were essentially flat.

That says that more people are consciously choosing ABC’s newscast, and many may be new viewers. It's not a case of “World News” appearing to do better simply because its competitors’ ratings are falling while it remains flat, which often occurs in close ratings races.

The risk, of course, is to make too much of this. Ever since Couric and Gibson took over their respective anchor seats last year, news analysts have warned it would take many months for longer-term viewer trends to become apparent.

Still, it seems to be a strong indicator. Gibson’s viewership has been increasing since his much-praised midterm election stint back in the fall, while Couric has stagnated in third place.

NBC News points out that ABC has the advantage of stronger lead-ins from its affiliates in many markets, where the high-rated “Oprah” gives stations’ local news a boost. That is so, yet it’s an advantage ABC has had for years and NBC still managed to stay ahead in total viewers.

More likely it’s a reflection of viewers’ connection with Gibson. 

What may be perceived as Gibson's weakness, a plain-vanilla delivery of the news, could well be turning out to be his great strength in an era in which the news is increasingly driven by personality. Gibson delivers the news straight out, where the focus is on the story, not personality or spin or faux analysis.

For people who just want the news, without the goop, that has to be a huge draw.  

There's certainly less of it on cable, where newscasts are defined by stylized anchors such as CNN’s Anderson Cooper and Fox News’ Shepard Smith. Viewers often have strong feelings toward them, negative or positive.

On broadcast, Couric and Williams are similarly perceived as strong personalities. Triple the percentage of respondents to a Pew Research Center study last year reported a negative opinion of Couric than Gibson. And while 16 percent tabbed Gibson trustworthy, none chose that word to describe Williams, though 5 percent did call him liberal.

Meanwhile, in daypart ratings for the week ended Feb. 4, NBC’s “Meet the Press” was first among Sunday morning shows, bringing in 4.32 million total viewers and a 1.2 adults 25-54 rating. ABC’s “This Week with George Stephanopoulos” was second in viewers with 3.30 million viewers but third among 25-54s with a 0.9, followed by CBS’s “Face the Nation” with 3.21 million and a 1.1, and Fox “News Sunday” in fourth place with 1.55 million and a 0.5 among adults 25-54.
 
In late night, NBC’s “Tonight Show with Jay Leno” was first for the week with 6.2 million average total viewers and a 2.0 rating among adults 18-49. “Late Show with David Letterman” on CBS had 3.8 million viewers and a 1.3 rating in the demo, with ABC’s “Nightline” bringing in 3.6 million viewers and a 1.2 rating. In late late night, NBC’s “Late Night with Conan O’Brien” had 2.5 million total viewers and a 1.1 in 18-49s, ABC’s “Jimmy Kimmel Live” had 1.8 million viewers and a 0.7, CBS’s “The Late Late Show with Craig Ferguson” had 1.7 million viewers and a 0.6, and NBC’s “Last Call with Carson Daly” had 1.5 million viewers and a 0.7 among 18-49s.
 
In morning shows, NBC’s “Today” was first with 5.9 million total viewers and a 4.6 household rating and 15 share, followed by ABC’s “Good Morning America” with 5.1 million viewers and a 3.9/13. CBS’s “Early Show” was third with 3.0 million total viewers and a 2.4/8.
 
In daytime, CBS once again had the largest audience for daytime dramas and full daytime, 3.98 million and 4.43 million respectively. But the network was third among women 18-49 for daytime dramas and full daytime with a 1.4 and a 1.3 rating, respectively. ABC had the second-largest audience with 3.51 million watching its dramas and 3.61 million for full daytime, and was first among women 18-49 with a 1.8 rating for both dramas and full daytime. NBC had an audience of 2.72 million for both dramas and full daytime, and was second with a 1.6 rating in women 18-49 for both.