What made this even more surprising was how his guests -- CNN's Gloria Borger, Politico's John Harris, the BBC's Katty Kay, and former "CBS Evening News" host Dan Rather -- seemed to feel she was.
Most bullish on Palin was Rather who said, "I wouldn't underestimate her...If she decides to run, it would be hard to bet against her for the nomination."
For his part, Matthews played a little bit of a misdirection with his viewers by predictably bashing Palin during the program's introduction (multiple videos follow with highlights and commentary):
CHRIS MATTHEWS, HOST: She was a governor that couldn't take it anymore. Ridiculed as a Bozo, all she could do was cash in get what she could on the way off the stage. But a year later, with zillions in her pocket, she's an even better bet to run.
As the opening segment about President Obama and Generals McChrystal and Petraeus came to an end, Matthews told his viewers:
What followed was one of Letterman's typically derogatory "Top Tens" about Palin:
MATTHEWS: Before we break, it was a year ago that Sarah Palin called that surprise news conference out there in the lawn in Wasilla to announce she was quitting as Alaska governor. David Letterman had a lot of fun with that.
After the commercial, Matthews played a clip from Palin's resignation speech last July:
SARAH PALIN: With this announcement that I'm not seeking re-election, I determined it is best to transfer the authority of governor, to Lieutenant Governor Parnell.
MATTHEWS: Transfer the authority? Well, she quit. A lot of people thought that was a short-sighted move, that quitting would end her career as an elected politician. Well, a year since then Palin's made well over $12 million. Her first book "Going Rogue" was the year's number one best-seller, made her $7 million in the advance. She gets $100,000 a speech, and Fox signed her to a TV deal. Besides getting to be rich, has she become, I would ask you open-ended, is she the most important Republican right now in the country?
Kay was the first to answer, making some surprisingly positive comments about the former Governor and her success assisting Republican candidates in recent primaries.
When Matthews commented that Palin seems to be only backing winners, Borger countered that maybe they're winning BECAUSE of her support.
For his part, Harris was a little less enthusiastic, but also gave an uncharacteristically upbeat view of the former vice presidential candidate.
But the best was yet to come when Rather got his turn:
DAN RATHER: Well, she's not running at the moment for President. But I wouldn't underestimate her. She's a version now of a Deacon with four aces. She can go a lot of different ways. She is playing an almost perfect hand. If she wants to stay a power in the Party, make a lot of money and not run, she can do that. I wouldn't underestimate her even for 2012 for one second. If she decides to run, it would be hard to bet against her for the nomination.
MATTHEWS: Good point. Is she Richard Nixon? Is she going around and picking up chits, proving that she can deliver, carefully selecting winners, avoiding losers when they're on the right, so that day after this election, like Nixon did in '66, "Look what I did for the party, I should be the nominee?"
RATHER: And goes into the convention with maybe thirty percent of the votes.
For approaching two years, America's press have been mercilessly eviscerating this woman with every opportunity.
Now, with Obama plummeting in the polls, and Democrats looking like they're in a lot of trouble in the upcoming midterm elections, suddenly Palin is not only possibly the most important Republican in the country, but is also a legitimate candidate for President.
Is hell freezing over, or is something else at play here?