On its own, Kinect probably hasn't been that much of a success, not with the huge investments in marketing, research & development, and the failure of most games outside the huge success of a select few. However, I think it's always been more important to Microsoft to achieve some measure of market penetration and brand recognition with this generation of Kinect in preparation for Day One integration with future generations.
Kinect as a core gaming device has always been a bit of a ruse. They did anything they could to get it into people's homes initially. I think they knew core gaming wouldn't be the future draw for Kinect but rather it's use to augment Xbox functionality. In other words, they want to use Kinect to expand the Xbox's place in the home as a multi-functional media box that appeals to a wide range of demographics. In that regard, I'm sure they're happy with it.
