I don't know if Microsoft will embrace it or not, but I think I can still answer a few of your questions:
Q: Does MS have the technology?
A: On the console side, the technology is nothing special, very simple actually. All you need is a powerful enough system to output at 120 frames per second, and the shutter glasses (really a 1-pixel LCD screen for each eye) which alternately block each eye's view, resulting in 60 frames per second for each eye from the correct perspective. In fact, the Master System from Sega already had a similar technology.
On the TV side, however, you need a TV which can not only display at 120 Hz (many already do), but also accept a 120 Hz input (few do, and they're not cheap). I think 3D-enabled TVs will be more rare than HDTVs were when this generation started. This is what makes it hard to say if MS will be interested, and if people will actually adopt it.
Q: Does Sony have a patent on it?
A: I don't think so, since Nvidia has already launched a 3D gaming product for the PC.
Q: Would you like to see Gears and Halo in 3D?
A: Probably, but I don't think I will have a 3D TV any time soon. I may buy a 3D-enabled LCD for my PC, any more than that is probably going to be too expensive in the next few years. Besides I probably don't want to wait long enough for prices to come down before upgrading my current TV.