If I were starting an agency today, I would probably call it a communications agency, not a PR agency. Our overarching goal would be to create communication strategies that help clients achieve business objectives. It would encompass internal and external, consumer and corporate communications, both online and offline.
By the way, old notions of "above and below the line" are obsolete on the Web. Communication strategies are media neutral and are revisited regularly; such is the pace of change. ...