From my perspective, even if Nikon and Adobe work out some kind of agreement and "play nice" so that ACR fully supports this model, encrypting the data is still unacceptable.
For all we know, some bright teenager may come up with an entirely new approach to color interpolation providing superior results. But, if a developer can't get to the data (or is afraid to for legal reasons), then it stifles competition.
Personally, I'm not going to buy a camera that encrypts any portion of the metadata, even if I have solutions available to decrypt it. It's just a matter of principle, and I don't like the precedent encrypting data sets.
What's next if we don't complain? Even stronger encryption with USB based security devices tied to your camera's serial number so that only a manufacturers softwarecan see the images from it? I just don't like the concept of encryption in images I take with a camera I bought.
Does Nikon have a right to do it? Sure. Do I have a right to avoid their products? Yep. I'll vote with my wallet.