In this Techrepublic article " Blogs vs. wikis: Which is best for internal government use?" Ramon Padilla Jr concludes that both internal and external blogs are

"more trouble than they are worth for widespread use in a government setting. However, I do think they can be valuable tools for specialized instances (such as the IT department creating a security alert blog on the intranet or providing blogs for elected officials to communicate with their constituents).

...blogging is not the best means of communication for government organizations, an internal wiki is a low-cost, very useful tool that every IT shop should consider adding to the environment. "

Check out the Web Site Starters for Windows, which includes includes Telligent's Community Server blogs and forums. COmmunity Server is what we use for this blog. Check out the explainer here.