I danced my clumsy white ass off at a Dance Central event a few weeks ago. Lucky for you, no video exists of that heinous act. Instead I'll use this gameplay clip to illustrate one of the best little things about Harmonix's Kinect-based dance experience: 

Notice the arms and legs on the avatar glowing red at the beginning of the video? That's how Dance Central lets you know you're doing it wrong. If a limb's glowing, then you need to reposition your own gangly appendage. You can also eyeball the small silhouette of your figure that appears on the right to see if you're accurately mimicking the moves displayed, but those glowing beacons are the main way Dance Central lets you know you're doing it wrong. During they songs I performed, they lit up pretty much the whole time.

After the event, I couldn't stop thinking about that tiny yet significant feature. It demonstrated to me how accurate and potentially game-changing the Kinect's motion sensors are. Dance Central simply wouldn't be possible using the wands and remotes of the Move and Wii.