The final bug in the .NET ointment will be the public perception of Microsoft as a sneaky company. People dislike being monitored. This is not because they have things to hide but because it's just plain creepy. Have someone stare at you while you're driving, for example. See how you like it.
Background monitoring by a computer is similarly creepy.
There is a distasteful aspect to the idea that Microsoft does not fully understand. People have already made it clear to Microsoft that the company is not fully trusted with individual information. For example, a fuss was made over the company's financial products, with people fearing that Microsoft would somehow become the world's banker and control center. People see tracking code in .DOC files and wonder what is afoot. The whole .NET concept stinks.