Not quite ready to jump into the Ubuntu 9.10 beta? Want to see what its subtly revised icons, themes and wallpapers look like? Being an open-source project, you can grab pretty much everything right from the source.
Head over to Launchpad, a bug tracking and development site used primarily by Ubuntu-related projects, and you can search out and grab any of Karmic Koala's wallpapers, themes, icons, or other pieces for your stable Ubuntu system—or, for the wallpapers, any system you've got.
You won't be able to utilise the auto-rotating space-themed backgrounds that come in Ubuntu 9.10, but a lot of the other picks are pretty snazzy. For Ubuntu users who particularly dislike the current set of icons, Karmic's batch isn't quite a unified, elegant whole, but seems like a step in the right direction.
Found other sources of pre-release Ubuntu art to share? Link it up in the comments.