Last night I upgraded to OpenOffice.org 2.3 and noticed that there's now a Weblog extension. So I'm testing it here. Don't expect much in the way of pithy comment.
The way this works is that you simply install the extension by double-clicking on it. Then when you open Writer you'll notice a new Weblog menu. Edit your settings by choosing the type of blog and entering your username and password. The extension publishes to Blogger, Roller, Wordpress, Atom Publishing Protocol API, and MetaWebLog API, and you can have multiple blogs.
Then just use your word processor to compose the post, complete with all of the nifty features. There's no need to title the work as you'll be asked for a title later.
When you're satisfied, click on “Send to Weblog”. In the dialog box that pops up, select your blog then enter the title, and a category, and select whether you want it saved as a draft or published. Click OK and you're done.
Seems to work.