Reader Mike, in the comments to yesterday's post, points out he's heard dubstep before, and pretty much all the rest.
Hey, Mike, where have you heard this before?
Panic! At The Disco: The Ballad Of Mona Lisa... by jimihubabua
I think the vocal bears an uncanny resemblance to one Declan McManus' Washing the Protectives, though I'm willing to concede they may both have had a common ancestor.
Also, it has Steampunk imagery, which I'm pretty sure Mr. Costello was too cool to get mixed up in. (I look at the Raconteurs funny too, when it comes to the Steampunk thing.)