Advertising part of PR?

As illustrated in the video, change is almost always incremental:

We were discussing marketing ideas for one of our clients.
A few years ago, we would have discussed banners, SEM, advertorials, sponsorships and other ways to push our message out to the consumer. Today we were talking about buzz, blogging, viral messaging, outreach, etc. We see the 'traditional online media' as a given and focus more and more on WOM techniques.

I would argue that the changes in marketing, communications and media are so pervasive, so fundamental and so dramatic that advertising agencies and PR firms won't be referred to as advertising agencies and PR firms anymore. They will be something different. Something new.

Let others worry about how we'll be calling this.
For now, let us just worry about great ideas. Ultimately, clients don't care where ideas are coming from. It's not about the delivery service, it's about the product