Design Team/Proposals/Journal

Datastore

 * See Sascha Silbe's version support project specifically datastore-redesign (click the raw blob data link at the top of the page to see the HTML rendered in your browser), and this mailing list thread, or this compilation of the discussion in context with the proposal document.

Tags under titles
CSA: If you incorporate ordered tags, based on filesystem paths, they could look like this:

Toolbar and palettes
See Gary Martin's mockups, such as this:

GMail-style tag view
Tags drag-and-drop-able from a left-side palette.