The chain of hat-tipping is particularly convoluted and random: Andrew Sullivan linked to an essay published months ago in Commonweal, which he'd found via this blog. I don't know this blog and have never seen it before, but it can't be all bad because it recently posted this video, which I decided I had to share with you right away.
My favorite part is the exasperated sigh Sherlock Hemlock gives John-John when he interrupts. Bert's subtle double-take when John-John takes over the segment is also awesome. Every time I watch Sesame Street now I grieve for the old-time muppeteers.