The title of the latest episode of 'Bones' was "Death In The Saddle", and it referred to the victim's corpse being left as if it was a champion race horse - his feet were ritualistically cut off and buried separately from the rest of the body; the hands had been lightly bound; there was evidence of a bit used in his mouth; and his stomach contents were of corn, raw oats and molasses (horse food).
When his name was revealed to be Edward Milner, Booth, Cam, and Hodgins all had a good laugh over him being "Mister Ed". Bones, of course, didn't get it.
Cam: "As in, a horse is a horse...."
(The others chimed in with the "of course, of course".)
Booth: "The famous Mister Ed!"
Luckily, none of them had to hit her over the head with it being a TV show, so we're spared a Zonk. Because long before 2007, Mister Ed was indeed famous in Toobworld. The secret that he had been a horse who could talk had long since been outed in some way after the 'Mr. Ed' series ended, but before the horse's death.
I assume there was probably some sensationalist news coverage over the story at first, but eventually the world probably came to accept the fact that a horse could talk. (I'm assuming the general public is still not aware that there is an island of such horses in the world - thanks to the TV adaptation of "Gulliver's Travels". It's the Toobworld contention that Mr. Ed was an escapee from Houyhnhm.)
Eventually, Mister Ed was offered the chance to capitalize on his fame, and he became known as the host of a nationally syndicated call-in radio talk show host (as seen in a broadcast but unsold TV pilot produced by Eddie Murphy - "What's Alan Watching?"). If I'm not mistaken, by that time he was living in North Carolina.
Dr. Cameron Saroyan was quoting the TV theme song, but again, this can be splained away. It wasn't used for a TV show, unless one was made about Mister Ed after he became famous. It was probably a novelty record by Jay Livingston and Ray Evans that capitalized on the fame of the talking horse.
And despite all the hoopla over the talking horse, somehow Dr. Temperance Brennan never knew the story while growing up.