Oh, wow this makes things easier!
If there's one gripe I have about Blogger, it's how difficult it is to see what your post is going to look like when you hit publish (their web preview does not show your backgrounds, columns, etc.).
The only thing I wish Live Writer had was a function to download your formatting options from your template's css styles, so you could just use your css options from the drop down menu that allows you to choose heading 1, 2, 3, etc. and paragraph.
With Windows Live Writer, you can compose blog entries that look like they'll end up looking as you type them.
I'm looking forward to posting this and seeing how the post looks online.
[EDIT] Perfect! I'm loving Windows Live Writer! It's also great to be able to compose a blog post while offline (say, while on a transatlantic flight), and then post it when you have connectivity again.