Nothing is going to change anyways. This is all just mental masturbation.
Advertising is a wholly deplorable affair in which all active participants (excluding the victims) will be "sent to the special hell where they will be skinned alive and set simple".
Look at how hard Big Entertainment is fighting the "attacks" on their advertising platform through purchased legislation, intimidation, harassment, collusion, and outright terrorism.
SonicBlue was sued out of existence for having the audacity to allow advertising to be skipped, which is not even the same as a true opt-out where the advertisers can tell their content was rejected. What was it.. Direct TV or Dish which recently said they were going to implement a skip mechanism and the brouhaha has already been started there. Big Entertainment has consistently demonstrated that they are willing to fire the lawyerpults and use insane arguments like skipping-commercials-is-stealing.
Hulu caved in like complete pussies and will start demanding that you have a cable subscription to access content like HBO already does. That's kind of like getting out of prison, but being forced to come back periodically to give a conjugal to Bubba because he misses you.
Microsoft makes only a small portion of their revenue from advertising, whereas Google makes how much of it from advertising? Of course they are not going to actually cooperate with any scheme or platform that drives their profitably down. It would be suicide as a business decision.
Microsoft turning on the DNT by default is basically a declaration of war (well we are already in one) against Google primarily, and the other ancillary business involved in online advertising, marketing, statistics, analytics, microtargetting, etc.
Lord knows why when it is such a stupid and pointless move.
The only way you are going to get privacy online and no tracking is to take it by force (technical methods are available), or hope that those whores in Congress, or your local whore at a state level implement legislation with real teeth.
Regular people do not want advertising. Anybody that says they do, should recuse themselves from the argument because they are clearly part of the advertising industry as either a client, or a provider.
The inevitable conclusion is that a war is being waged, and will be decided, by technology. People want technology to remove advertisements and unwanted content from their lives and have always demonstrated that the moment the barrier to entry is lowered enough (average level of sophistication and availability) they use it.