Just got my Nexus 7 last night (very impressed, BTW) and I've been scouring the Play Store for note-taking apps.
On my Droid Bionic, my not-taking app of choice is GNotes because of it's minimalist design and its robust input methods (text, handwriting, drawing, voice, and photo.) And it syncs to either Gmail or the GNotes Web site providing a nice backup and sync across devices. GNotes works very well on my Nexus 7, though it's not a true "tablet" app--it renders simply as a large phone app.
While GNotes may end up being my Nexus 7 note-taking app of choice, I'm interested in your suggestions and experiences with other note-taking apps.