Doubtful as they lost the HD-disc Vs Blu-Ray disc war way back, due to porn and Sony backing Blu-Ray(Mostly due to porn backing Blu-Ray) and the money they had invested in HD discs and the company shares they bought backing the HD disc format, that turned out to be worthless, I can't see MS venturing down that road again.
I just pulled this off of
http://forums.highdefdigest.com/high-def-disc-faqs/91283-who-owns-blu-ray.html It's worth noting that Panasonic holds the most patents in the technology at this time, and it appears that the BDA will adopt Panasonics 3D Blu-ray model, so Panasonic will likely hold more patents in the technology still.
Sony holds the most patents related to the disc design structure which potentially will garner them the highest profits on the technology. Where Panasonic gets paid for every player sold, Sony gets paid for every disc produced. Per unit they get less, but overall they will get more.
At least, this is my understanding after following BD for years.
There are other players in BD as well, for sure, but I'm not sure if any come as close as Panasonic or Sony for patents in the technology.
I can't see Sony releasing there stranglehold anytime soon on the format let alone for MS to creep in and secure the relative patents. Digital Download seems the way forward for MS, or serious corporate espionage either/or.