Microsoft is currently shipping a Kinect sensor bundle for the holidays, which includes three games for $150. The included games for North America – though they "may vary by region" – are Kinect Adventures, Fruit Ninja Kinect and The Gunstringer, from Microsoft's newly acquired studio Twisted Pixel. Considering the $40 Gunstringer retail box contains a free Fruit Ninja Kinect, it might be easier to think about this bundle providing a $40 savings.
Microsoft has been playing it close to the chest regarding Kinect sales this year, recently reiterating that the device had sold 10 million units, a statistic it already promoted in March. We'll get another update after this year's bundle-boosted holiday sales have been tallied.