With around 15 years' industry experience, I'm a PR practitioner and former journalist (Computing, The Register, Daily Mail and many more). I've run my own business and worked with some of the world's biggest brands (such as Microsoft and HP).
Like many people, I think the boom in social networking (blogs, Twitter, whatever) offers significant potential to businesses and individuals alike. But I would caution against anyone touting themselves as an online / social media expert; just be careful who you buy your snake oil from, that's all.