I've said this time and time again, Microsoft really needs to beef up their 1st-party portfolio. They did rather well during the early years of the Xbox brand, with games like Conker Live and Reloaded, Jade Empire, Geometry Wars, Hexic HD, Banjo Kazooie: Nuts and Bolts, Perfect Dark Zero, Kameo, Gears of War [as publisher], etc.
But ever since they released the Kinect, Microsoft seems to have completely switched focus. The Xbox has become an all-in-one entertainment/media hub, with Kinect being the center of it all. This has (inadvertently?) resulted in a lapse of 1st-party gaming content.
I guess in a sense, Microsoft is the new Nintendo. They went from fully supporting the dedicated gamer, to releasing a camera peripheral to cash in on the Wii's motion controller success. The problem is, no one expected (or asked) Microsoft to do this. Kinect is a laggy, unresponsive technology that makes the Wii Remote look like a godsend in comparison. No amount of bodily flailing or pantomiming will improve the gaming experience if the hardware can't keep up with your movements.
Microsoft now has only 4 main franchises to rely on: Halo, Forza, Gears, and Kinect Sports (I know Gears of War is an Epic Games IP, but Microsoft publishes it). Where's the diversity? They can't compete with Sony on the 1st-party front, because they aren't showing the effort to match Sony's output.