Dare writes about Blogging from Word 2007. This is in Beta 2 which will be available externally in the next week or two. Joe Friend describes how to do it.
In Beta 2 it works with MSN Spaces, SharePoint 2007, Blogger, and Community Server (which is used for blogs.msdn.com). You can also set up a custom account with services that support the metaweblog API or the ATOM API.
What a cool new feature!