It’s not commonly known, but Miller is crazy for anagrams–in fact, her pet name for Lewis Libby is “Wily Bibles.” So it’s only natural that he’d choose this form to communicate in secret.
Take the best-known phrase that appears here: “The aspens will already be turning.” This anagrams into “repugnantly brainiest swellhead” — a clear reference to Karl Rove.
“They turn in clusters” anagrams into “truth incenses truly” or “truth n’ rusty silence” — each referring to Miller’s refusal to testify before the grand jury without Scooter’s approval. An alternate anagram is “nuts! the surly cretin,” which may be a veiled reference to President Bush.
Finally, “because their roots connect them” translates into “the erotic obscurement aches not” as well as “bitch the concrete, treasonous me.” These of course, may be Libby’s way of saying “our love will survive as long as you keep my role obscure,” or possibly “drop a dime on me and I’ll punk yo’ ass, bitch.”