Visit DigitalGrit.com and you'll see more than snazzy images of entrepreneurial types. This marketing company (not unlike Hill and Knowlton) helps businesses use the Web to make more money through increased product visibility. How could this help your company's blog(s)? I think the main advantage lies in the third-party expertise you'd be getting. DigitalGrit can help you with everything from coming up with a good blog name to honing an effective RSS publicity campaign.
If you're a business owner itching to blog but wondering how to make it worth your time and money, you should at least take a look at companies like DigitalGrit and Hill & Knowlton. If their services are too pricey, hey, you've always got free advice from resources like Business Blog Wire.
See DigitalGrit's corporate blog, Getting Granular, for company news and insights. (I haven't reviewed their blog just yet, but you can read my review of Hill and Knowlton's blog for the time being.)