They tend to make bigger deals out of the fifth anniversaries than they do the tenth anniversaries. Both Season 25 and Season 35 had specials associated with them, and 35 had a ton of merchandise tie-ins.
I've been looking at the Muppet Wiki page on the shows anniversaries, and it seems every anniversary since the 25th has had a lot of merchandise and publicity and such. In fact the 25th and 35th anniversaries both had two specials each (and one of the two 25th anniversary specials had two different versions, making it what I call two and a half anniversary specials). I wonder if there'll be two 45th anniversary specials (yeah right, unless we count 40 Years of Sunny Days as a special we didn't even get one 40th anniversary special).
It also seems like, with the exception of the 10th anniversary, only the anniversary specials in multiples of fives get anniversary albums (and since season 30 only multiples of ten get special books).
I was happy that we got a special DVD for the 40th anniversary. In fact before it was even rumored I started a thread wishing for a special DVD set (though if it was up to me, it'd be a four-disc set, with each disc representing a ten-year period). But even though it was two-discs I figured they'd be able to represent everything I thought was important to include, especially since there wasn't any true linking footage. I was very surprised that it didn't include anything with Biff and Sully, Guy Smiley, Don Music, Gladys the Cow, Sam the Robot, or Sherlock Hemlock, that it didn't include any Jazz Numbers segments, heck I even thought it would have been essential to include Buddy and Jim, Larry and Phyllis, Wally and Ralph, and all of the "season three" characters (well Rafael did appear in the Bienvenido Song).
If such a two-disc set were to be made for the 45th or 50th (or later) anniversaries, I wonder if it'd be harder to squeeze in all the important stuff on two discs. All the best unreleased clips, all the stuff that pretty much needs to be in every anniversary (whether the collectors want more copies or not), all the best-remembered characters and recurring segments, especially since most companies these days seem to prefer two-disc collections (Old School Volume 3 was scaled down from three to two discs), though season 45 is only a few more years, I'd be willing to have less bonus features if it meant more unreleased classic-era clips, and at least for the 45th anniversary there'd only be five years worth of material, when the number of episodes per year are shortened and therefore the number of inserts introduced since isn't that big (if they don't include full street stories or full episodes of all the short-form series).
One idea I've thought of that'd be a cool option for fans, though I don't know if it's too realistic (and maybe better for the 50th anniversary... BUT I DON'T WANNA WAIT SIX MORE YEARS!!!!!) would be if they put out multiple two-disc collections throughout the year. Maybe give them titles like "Sesame Street Gold Collection", "Sesame Street Silver Collection", "Sesame Street Platinum Collection", and "Sesame Street Gems Collection", or something along those lines. One collection could be all of the show's most essential and biggest fan favorites, another could be full of fan favorites and obscure rarities (including segments fans like us might not even be aware of to request), one could be a handful of complete episodes ("Goodbye, Mr. Hooper", "Miles gets adopted", "Maria and Luis get married", and "Slimey lands on the moon" all seem like good choices) and maybe some bonus clips, and perhaps a two-disc collection devoted to all the recurring segments. Like one disc containing all the short-form shows (Elmo's World, Elmo the Musical, Super Grover 2.0, Abby's Flying Fairy School, etc.) and the other disc dedicated to the other (mostly classic-era) recurring bits, maybe multiple Sesame Street News, Waiter Grover, Super Grover and Monsterpiece Theater, and at least one each of all the others (maybe multiple Typewriter, Suzie Kabloozy, Teeny Little Super Guy and Fay ray segments).
Man, I sure am good at getting myself excited over my own wishful thinking.