A lot of people are doing things with zooming on existing data, where the zooming is a purely exploratory feature. You see fewer examples of creation tools in a zooming context. I mean, Photoshop lets you zoom in and out of its canvas, but in terms of zooming UI, it’s pretty rudimentary. Prezi is a good example, and even my Infinite Canvas counts, simple as it is.
The folks at Aviary are doing some amazing things, bringing creativity apps to the web. In terms of zooming interfaces, check out their Peacock, which has a zooming canvas for you to lay your effects patches onto. Interestingly enough, unlike Prezi or Infinite Canvas, the zooming canvas is just a behind-the-scenes organizational tool, rather than the image itself.
Also of note, since it’s a web app, they’ve got the community built in, including the easy ability to derive new works off of other people’s creations, and to track and explore the “family tree” of any work (much like AppJet). This distributed collaboration model seems to be gaining steam, and I definitely see it as the future of creativity.