Media as field with fields attached to the media (i.e. captions on images)

Woohoo, got this working.

Install fresh from the media_dev profile for a nice example. I've added the tags field and a description field by default to every media type.

To try:
1. Upload or add from URL
2. Go to admin/content/media and edit the media object.
3. You'll see the tags and description field, fill 'em out

4. go to view, you see 'em there!
5. Now create a Multimedia Asset field on a node type (say article)
6. Create a new article and attach some media.
7. display, voila!