Seeing that  Onenote can't import PDF (what did you expect? It ain't a MS format....) I was out looking for better stuff. There's PDF Annotator but that costs money and works kinda weird.

So finally I stumbled  over Jarnal

A Java based note taking app that can use PDFs as background (at least ;) and also export to PDF again. Only bad point: handwrite recognition is nigh unusable (one of the few things MS ever did right it seems) but just to scribble notes into PDFs that not's so important. It being Java also means I can view the stuff on Linux or whereever, really.

I doubt Crossover Office 5 (even tough it touts Office2K3 support) will do much good for Onenote/Tablet users so for the time being I'm locked to Win it seems.

Note to self: must buy RAM. Lots of it.