This is always the question around this time. While nothing has been set in stone, you can see the specs that are being considered on the Launchpad page for Gutsy.
I should note that this doesn't mean that everything on that page is going to be done. Any specs marked deferred mean that the implementer couldn't get them done for Feature Freeze, in this case August 16th, as can be seen on the Gutsy Release Schedule. You can look at the equivalent Feisty, Edgy or Dapper pages to get an idea of what these pages look like after release.
And, Steve, the page you are looking for is the Displayconfig-gtk spec