If Kinect isn't accurate enough for you, Microsoft is working to fix that.
Microsoft's Kinect can currently detect its players' full body motions so they can dance, bowl, and pet furry felines. However, its resolution has been questioned for use in games that require more accuracy. According to Eurogamer, Microsoft is working on it.
Kinect's abilities are managed by its firmware, which for now has the depth sensor set at a limit of 30 frames per second at 320x240 resolution. It's been determined that the sensor is capable of more, but there are issues with the Xbox 360 at hand.
The depth sensor could potentially be upgraded to 640x480 resolution by a firmware update, which could allow Kinect to detect individual fingers and hand rotation. The reason Microsoft hasn't enabled this yet is because of the Xbox 360's USB interface that can only manage a certain amount of data. Improving Kinect requires that it be able to transmit more data through USB.
The USB interface currently uses around 15 MB/s, but in theory that amount could go as high as 35 MB/s. Microsoft is working "very hard" on a solution to "free up additional bandwidth," Eurogamer says. Still, a major Kinect improvement may not be possible with the current Xbox 360 hardware if other issues pop up. MIT seemed to prove that Kinect could detect individual fingers with its Minority Report hack, so if Microsoft can rejigger the Xbox 360 it's possible that we'll someday see actual games using a higher level of Kinect accuracy too.