At SXSW, one of the audience members in one of the panels asked something like:
The simple answer: Not in the slightest.
The reality is that we don’t tend to see companies as groups of people, working hard to do something cool. We tend to think of "companies" as that big cold corporate entity in the sky. If your company has 3000 bloggers actively blogging in a way that your customers can find about nothing more than what their hobbies are, you’ve done something amazing. You’ve introduced yourself to your customers. The next time they think about yelling at customer service about a faulty product, they’ll be thinking about Jim the mountain biker who works in the call center, not that damn company who can’t spit out products that actually work.
Now, that said, if you can get your employees blogging about their work as well as their hobbies, even better.