Built Sesame Street with my six year old over the wet weather a week back, she can't stop playing with it and she has never been a massive Sesame Street fan. It's a very well designed play set that is very hardy, not something I can say for most "play" sets, even Ninjago and friends often have too many bits that bump off or collapse easily.
I'm not a big fan of saying "blah blah needs a CMF series" but this set shows that making Muppet/Sesame Street figures isn't too difficult and I'd love a 10 figure series with the count, Grover /super Grover, tele, Rosita and other humanoid Muppets (surely a Hooper and Maria too)... Failing that, combine it with Muppets themselves...
-edit-
Forgot to mention that using the heart piece in orange with a unique print for Smiley the worm may be my favourite printed piece ever...