I was thinking of something for more previews in the web browser, like when you hover over a picture, you'll get a little pop-up like thing that has a larger preview of the picture in it.

Now for something a little more...far out, maybe something for video that's like the hovering over a music file, such as a short preview of the video (like 10 seconds or something.)

Someway to preview text files (this would be VERY handy for me, a writer, who has a million different documents that relate to each other and I can't tell notes from the actual story itself, so that would be helpful.)

Overall I think it would be a great little feature for nautilus.