Btw, I'm not defending Google, they're clearly not acting perfectly here. I'm simply pointing out that this is a clear case of, "what did you expect to happen?" Any spec that still sets a cookie that is declared as not being used for any purpose seems deeply flawed.
I also found it interesting that Microsoft called out Google and not Facebook, which gives the article a political overtone.
I agree that P3P clearly needs some rethinking to stay relevant. Especially now that the cat's out of the bag on how to bypass it. (Microsoft's immediate response is to set up yet another blacklist system... some cultures just never change.)
For everyone's entertainment, the OP's comments linked to an amusing satire of P3P called P5P, or the "Pretty Please Platform for Participating Publishers." This is possibly the best collection of protocol tokens I have seen since RFC 2324.
I think MS probably needs to acknowledge that P3P is broken, and change the default so it doesn't affect third party cookie acceptance. Administrators for Windows environments that think otherwise can override the default by deploying a group policy.