At first when I read it, I thought it said that Harry gets stepped on by the rabbits. But either way, that's the way to do it.
The opening theme bits were just right, opening number and corresponding backstage bit with Gonzo & Beautiful Day worked well, all the songs worked well, Wayne & Wanda was original and funny, I loved the Muppet Labs bit where Bunsen is dragged away by a dogcatcher, and I really loved the goodnights and closing comment.
Talk spot worked pretty well- typically TMS was not very self-referential with their un-named spots. The Talk Spot was called as such just once, so having them call it the Talk Spot a few times calls attention to itself IMO, at least it would've on the show. One more minor thing- Kermit's intro to "Moon River". It doesn't read like the show, as in Season One, Kermit rarely mentioned the song when introducing the guest star (often didn't even mention it for opening and closing numbers). Usually just prefaced his intro with some good words for the guest (ranging from small compliment to gilding the lily) and then "ladies and gentlemen, Mr. Harry Secombe."
I agree that the bulls comment was a bit too long, also the second backstage scene. The part of that scene with Harry & Piggy doesn't really go anywhere, it isn't really necessary. Two quotations that have stuck with me are "Brevity is the soul of wit" and the oft-used "less is more". Generally, if you can keep a funny bit short and tight, the joke is not only more smooth and fluid but the timing of it works that much better because there's less clutter in the way. That's something that only comes with practice, trust me on that- I've been writing comedy since I was 12 and only in the last few years have I started to show promise (of course, finishing puberty and experiencing life helped).
That's my two cents for ya. Sorry it took me so long to read it, I haven't been to MC much lately.
David "Gorgon Heap" Ebersole