Well, since I didn't get that email, and since it sorta seems like I would be in the target demographic (AdWords user who usually opts out of the content network), I guess I will take the term "vigorously" with a grain of salt until I find out the vast majority of AdWords accounts got such an email and I was just unlucky.
It's encouraging that they (finally? eventually? at long last?) decided to try to counter the nearly set in concrete AdWords conventional wisdom that the content network should always be avoided. Hopefully, they have a new department working on that problem every day, not just a single email...
I belong to a trade group of small businesses that make extensive use of AdWords but virtually never use the content network (interestingly, they never use Google CheckOut either despite being prime candidates, since a few bad initial experiences completely poisoned the well). I'll know Google made some progress as soon as I see a single post there relating a positive experience with the content network.
Fixing the content network perception problem is completely outside of Google's core skillset, IMHO, and I doubt they have a snowball's chance in hell of making a dent in it unless they give it a high priority (money/prestige) and hire some outsiders with non-Google mindsets to run it. When you build your business model on letting your machines handle customer interaction, you're just not going to be in a position to handle problems that require extensive customer persuasion.