Personally, I think there needs to be one, anchor Twitter account, and it has to be YOU. Not the blog, not the company, but you the person. You can (and should) still tweet about the blog, the company, and the industry (because that's part of who you are), but if I don't see some authenticity, I won't follow. That's where you should build the relationships and the following. Then you can create some other, more branded twitter accounts that you use to automate dissemination of posts and other information. My two cents from a non-marketer but early Twitter adopter!