For the record, I'd like something to replace notebooks. I'm accumulating more and more notebooks, and they're a pain to tug around everywhere. Plus, notebooks are easy to get lost (I've lost notebooks by accidentally leaving them in restrooms), not easily-backup-able, and non-searchable.
So I'd like a tablet that allows me to read PDFs heavy on math/physics, that allows me to easily annotate notes, and that has a thin stylus that allows me to write subscripts and superscripts with ease.