The Stephanie Miller Show (nationally syndicated, and on the air here in Madison) has developed a formula or construction that is almost a snowclone. It's a name, of this sort:
X-y Mc-YZEach letter is a monosyllabic word. These are coined to mock scandal-ridden Republicans and others. Most common are the lecherous Squeezy McFeelpants and his international pals like Scottish/English Mashie McGrabass/McGrabArse, along with Drunky McPukeshoes, a slam at Tom Delay (who is usually played in sound clips where he slurs words). Former White House "official spokesliar" Scott McClellan was Puffy McMoonface. (Note the little capitalization issue: I'm tempted to start both elements of the last name with caps.) They've talked on the show about these formulas, toying with ideas for how to name particular people.
I noticed a while back that Jon Stewart had used this formula, I think with some original form, though I don't recall what it was. Now, whitehouse.org has Bush talking about the death of Jerry Falwell, calling him "beloved McJesus huckster".
Wonkette has been ragging hard on John McCain of late, calling him Walnuts in part as an allusion to the view that he's crazy. This could easily have become X-y McWalnuts, but they've left it to their readers/commenters, who did it with a twist: McBatshit McCrazy.
The established use of productive mc- is clearly pejorative: mcjob is the best known. Go to Urban Dictionary and you'll see that most of the items they list are directly connected to the source form: McDonalds. Many, in fact, are about people with mcjobs or the work itself: mcslave, mctard, mcshift, etc., and most of the rest about bad food and its effects, like mcsquirts. The image above (from here) gives you the picture.
The whitehouse.org usage surely still aims at the cheap/sleazy, franchise/commercial aspect of Falwell's ministry, but the Stephanie Miller Show has built it into a bigger construction and made it more political. Is there more evidence out there on this? There must be.
Update, 9:55 am, by Joe: ads-l has a thread starting on this topic probably within an hour of when this post went up. Grey's Anatomy apparently has some thing about "McDreamy" (according to a message from Mark Peters), presumably in a different meaning from the 'sleazy' or specifically 'politically reprehensible' ones.
Grey's goes back to 2005 (maybe Stephanie Miller was doing it earlier? Or got it from there?) and has a string of mc-'s without negative connotations, it sounds like. Best, though, is a note from Alice Faber on ads-l: "Stitchy McYarnpants' blog goes back (at least) to September 2004." Man, don't you need a knitted 6-pack holder?
Update, 1:00 pm: Damn, Language Log covered this topic last year, and I didn't even think to check. Oh well, kind of Sloppy McSlopperson, I guess.