Just as we speculated, those early shots of the DJ Hero controller weren't showing the whole thing. That was being saved for, what else, an article in Game Informer magazine.
In addition to the turntable, there will be a second, clip-on component, which includes a cross-fader, effects dial, "Euphoria" button (ie star power) and the requisite d-pad and control pad buttons, which are hid tastefully beneath a flip-up cover. Unlike the silver turntable, this pad will come in a muted, metallic gold scheme.
Also revealed in the mag is how the game actually works. It's mostly like Guitar Hero, with notes cascading down the screen towards you, however this time around there are only three notes, with complexity coming from the fact that in addition to hitting those three, you need to have the cross-fader in the right position. Replacing sustained guitar notes will be scratching sections, with small arrows in the coloured line telling you which way to turn.
Finally, the article mentions a few confirmed tracks for the game. I'll warn you, if you're approaching this game with any semblance of pessimism or doubt, do not read any further.
"Feel Good Inc." (Gorillaz) vs "I Heard It Through the Grapevine" (Marvin Gaye)
"Jayou" (Jurassic 5) vs "Rockit" (Herbie Hancock)
"Bustin' Loose" (Chuck Brown) vs "Time of the Season" (The Zombies, DJ Shadow Mix)
"All Apologies" (Nirvana) vs "Give It to Me Baby" (Rick James, DJ Shadow Mix)
"Let's Dance" (David Bowie) vs "Jack of Spades" (KRS One, DJ Shadow Mix)
"Shout" (Tears for Fears) vs "Pjanoo" (Eric Prydz)
Nirvana vs Rick James? Oh dear.
[thanks to everyone who sent scans in!]