Here's a story about it from zap2it.com:
Big Bird Flaps Wings to 'West Wing'
(Thursday, February 12 04:28 PM)
LOS ANGELES (Zap2it.com) - Elmo could meet Leo.
Zoe the Muppet could meet Zoey Bartlett.
Somebody, apparently, has told the cast of "Sesame Street" how to get to Pennsylvania Avenue. Several of "Sesame Street's" most popular residents are about to visit television's most popular political drama when Big Bird, Elmo, Zoe and Rosita guest star on "The West Wing."
The Wednesday, March 3 cameos will mark the first time that these Muppets have guest starred on a prime time series.
In the episode, President Bartlett (Martin Sheen) enlists C.J. (Allison Janney) to try to improve the First Lady's (Stockard Channing) image. As a solution, the First Lady films a public service announcement where she gives Elmo a checkup.
If this crossover is successful, perhaps The Count will be called into the Oval Office to help out next time there's a key vote in the House.
"One Republican Senator crossing party lines... Ah-hah-hah," he might say.
This year marks the 35th anniversary of "Sesame Street."
I never watch that show but I think I'll make an exception this time.