Mine is airing this Friday.
Looking at the promo, as well as the confirmed interviewees (most of them celebrities, though it does say some puppeteers will be interviewed, though not who, exactly), I wonder if Sesame Workshop is actually involved with production on this. It's hosted by a celebrity guest as opposed to somebody from the show, and all of the old school clips in the preview are ones shown in the Old School DVDs (though there are a lot of clips from after season 15). I'm not sure if this is the kind of program where they could just pick clips without permission (though by that logic, they could just use clips posted online... though then they'd have the sesamestreet.org logo), or if PBS actually has broadcast rights to the use of old clips. Or maybe I'm overthinking things again.