Torn on this.
If Google are only going to collect data via their first-party relationship with users, and block everybody else from tracking then this sounds like a great idea to me personally: I use none of Google's services, so that would be a win for me. However I simply don't believe that they'd only collect data that way, so on balance if Google think this is a good idea then it probably isn't - when the biggest data-slurper on the planet starts talking about user privacy my bullshit meter goes off.