Remember that “secret legend” NBC’s “Today” show promised it would trot out Monday – the person so legendary, and secret, you should watch them instead of Katie Couric returning to morning infotainment as guest co-host for a week of ABC’s “Good Morning America”?

Well, it was not Will Ferrell in character as Ron Burgundy announcing – again – he’s going to do an “Anchorman” sequel, as some had speculated excitedly.

Nor was it any descendant of “Today’s” famous founding co-anchor chimp J. Fred Muggs, or any old chimp dressed up as Katie Couric, or John Legend – among the guesses people had logged after NBC issued its tease.

View Photo Gallery: Former “Today” co-host Meredith Vieira said goodbye to her colleagues and viewers on her final show.

The “surprise legend” was former “Today” co-anchor, and current NBC News contributor Meredith Vieira.

Katie’s week-long guest gig on “GMA” is expected to end its more than 16 year weekly winning streak in the ratings. “Today” has also booked Sarah Palin to guest host – but Tuesday only.

(Read updates from the TV Column’s live blog of Katie’s appearance here.)

UPDATE: Katie Couric Tweeted oist-”Today” and “GMA” Monday broadcasts about getting cozy with Matt Lauer in Times Square

Meredith, you’ll recall, was “Today’s” first post-Katie co-anchor but left when her contract expired and now does this and that for NBC News, including reports for its struggling “Rock Center” primetime newsmag.

Anyway, “Today’s” secret legend has an announcement:

“Today” anchor Matt Lauer to Meredith: “The reason we wanted to have you back is we do have what we think is a great announcement, it’s something that’s going to be affecting us and our viewers in the coming months.”

Meredith Vieira: “It’s great for me, I’m going to be joining you all at the Olympics, and I’m very excited, in London. In all the things I did I did in the ‘Today’ show in five years, I think the Olympics is my very favorite experience.”

Yes, the big announcement turns out to be that Meredith will be part of NBC’s Olympics coverage team.

Time to phone tomorrow’s co-host, Sarah Palin. You know – the vice presidential candidate publicly humiliated when Katie Couric interviewed her and asked her what newspapers she read to stay informed and Palin did not name a one?

Matt Lauer: “We did read a tweet you sent out, ‘Going to go rogue and infiltrate some turf.’ What exactly does that mean?”

Sarah Palin: “What do you think it means?”

Al Roker: “You’re taking over Matt’s dressing room?”

Matt Lauer: “What are you doing to prepare, are you reading some newspapers?”

(round of “ooohhhhhs”)

Al Roker: “And it begins!”

Natalie Morales: “You can still turn that plane around, Governor.”

Sarah Palin: “That’s a fine ‘How do you do,’ that’s a great start!”

A little more lively banter later, Palin gets serious: “I really look forward to this. I appreciate NBC’s boldness in having me on.”

“And doesn’t it kind of reflect the kind of diversity of opinion that I hear that you all espouse?” Palin asks rhetorically.

“Or desperation,” Meredith mumbles.