The sound quality of the first generation was pretty cool - I played with one in a showroom. It was just window-shopping on my part, I don't have one iPod, let alone two. From the technological side it's not a very difficult thing - there's more than enough bandwidth through the ipod's dock connection to suck the songs through quickly (regardless of bitrate), and from there they'd live in a memory buffer in the iDJ2 (which allows it to be cued, sped up, slowed down, pitch-shifted, etc like a regular CD).

Now if you really want to be a sick bastard and money is no object, check out the $1500 priced HDMix. It has interfaces for ipods, USB hard drives and other devices, and a CD drive. But it also has an on-board 80GB drive. You can load tracks from any of the previously mentioned sources, and the mixer plays from the drive, the internal CD, or any of the many other inputs (you can run turntables and other CD players etc into it). It has two full transports with shuttle/platters, too, so you can manipulate tracks that are on the drive (or on an external USB drive), too. And finally, you can record whatever the fuck you're playing directly onto the on-board drive.... So very sick... very very sick...

~Trilo~