Yes, indeed, it is true. The New York Times chronicles (free reg.) how the blogging phenomeon is impacting the world of advertising and marketing.
From the piece:
The biggest fear is an uncontrolled message slipping out, said Steve Rubel, vice president for client services at CooperKatz & Company in New York, a public relations agency with clients including the Association of National Advertisers, J. P. Morgan Chase and Wendy’s. “Do they allow comments or do they not? Is there an implication if it is a publicly traded firm? Who is the one who should blog for us? How might that choice be received in the company?”