I just love OneNote. I did hint at this a while back but in my current Office build, 4228, this is all working really well so I thought I'd walk you through it. As James Governor said when I showed him,    

"It struck me, when he showed me blog publishing, from OneNote (a great, if proprietary app), through a Word widget, that Microsoft's competitors - and various upstarts, have all done a lame job here...The mainstream is just looking for something easy. If Microsoft can provide a slick connection mechanism to other blog platforms, through Word, it could have a reason to upgrade on its hands"    

So start in OneNote, write your post which is a much more natural environment to write a post anyway. You can create a scrap book of you thoughts, paste in links and move stuff around until your post is written. This can include pasting in pictures and hyperlinks too of course. Also doing it this way means you can easily keep a backup of all your posts in your notebook just in case the unthinkable happened and your blog got nuked in some freak accident.

Here is what this looks like for the SharePoint post I posted yesterday:

Then all you do is right click and "blog this"

   

Which pulls the content into Word using a blog template file. Which looks like this:

  

Then you can pull down this menu from the publish button:

 

And if you publish as a draft it posts it to your blog as an unpublished post. In the process it also posts all the pictures to wherever you store those - in my case on a separate SharePoint server. Easy as that.

Now if you want to see how to set that up you can click on manage button.

Click New..

These blog providers are supported out of the box. The Other option though enables you to configure it for :

The Other option though enables you to configure it for other well known blogging platforms, with some beta 2 caveats:

Provider API Known bugs
dasBlog Not Supported in Beta 2 will be supported in the future.  
LiveJournal Atom Categories will not work
TypePad Metaweblog Categories will not work
.Text Not Supported in Beta 2 will be supported in the future.  
WordPress Metaweblog Categories will not work Post date is incorrect

Just fill out your details - full details on how to configure it are provided in the link and more on uploading picture at the other link.

Stunningly easy :-)