Awesome. When the OneNote SP1 Preview first came out, I thought about writing a managed wrapper for the Importer API. Luckily, David, Donovan and Omar saved us all the trouble (details here). I guess I'll have to find some time to play with this one soon!
Of course, I'm still waiting for the Exporter API, but this will be nice in the meantime. Now to get SharePoint running on my home machine so all my notes are centralized!