It's Dance Dance Revolution - but with the moves built from your own personal music collection.
So how much fun you'll have pretty much depends on your CDs. Two things, though. One: can the Wii read music CD's, or will Dance Factory have to suck in its music from the USB port? Secondly: we'd assume that Codemasters are porting it over because they see possibilities beyond just dusting off an old dance mat, and judging by the PS2 version's obsession with calorie-burnage, we could be in for a rough time.