“Cute as the dickens” is not mentioned in the reference below, but I believe that in our expression it also means “devil,” but in a less negative way, as in “devilish” and “mischievous” – “cute as a devil.” “You little dickens” is another expression which I always took to mean “You little devil” in the positive sense. The thing that makes me a bit wary here, though, is why this sense is not included and only the “mild oath” aspect is discussed. I would assume that Jesse Sheidlower is a very careful fellow (now an editor at OED) and I wonder if there is not some reason why he left this out.
From The Word Maven at http://www.randomhouse.com
Dickens is used, usually following “the,” as a euphemism for "the devil" in mild oaths having various forms.
The earliest example known is found in Shakespeare: "I cannot tell what the dickens his name is" (“Merry Wives of Windsor”). Some other examples to show you the range of use: "What a dickens is the Woman always a whimpring about Murder for?" (John Gay, “The Beggar's Opera”); "What the dickens is wrong with you?" (Stephen Crane, “The Red Badge of Courage”); "How the dickens could he let the public know how truly great his president was?" (Sinclair Lewis, “Our Mr. Wrenn”); "I thought the vein or whatever the dickens they call it was going to burst though his nose" (James Joyce, “Ulysses”); "That hurt like the dickens!" (my father, a few weeks ago).
“Dickens” is almost certainly an application of “Dicken,” a diminutive of “Dick,” itself a diminutive of the male given name “Richard,” with “dickens” and “devil” having the same initial sound. Compare the slightly later “deuce” used in the same way, or, for another example of a euphemistic use of a name with the same initial sound, the substitution of “Jehoshaphat” for “Jesus” Another example of an “altered” name as a euphemism for "devil"-type words is “Sam Hill,” as in "Who in Sam Hill are you?," an Americanism based on “Solomon” as an oath and “Hill” as a euphemism for “Hell.”
Reply from Ken Greenwald (Fort Collins, CO - U.S.A.)