The Install Guide should no longer refer to "firstboot," but rather to the new "Initial Experience" being planned for Fedora 18. Refer to the feature page: https://fedoraproject.org/wiki/Features/InitialExperience
Initial Experience is now targeted for Fedora 19: https://fedoraproject.org/wiki/Features/InitialExperience
Added in commit 66e7a4133fec26f1d120412b203a6b207c33b6bd. * Added a mention in the admonition in 9.16.2. User Creation * Added a new subsection in 9.17. Installation Complete briefly describing the initial setup process, including an admonition pointing out that this is only available with GNOME, and a screenshot of the initial setup screen. I don't think it's necessary to document every available screen, especially since the application is made to be easy to use and there's not a whole lot of available options. I'd document a way to run it again, but the steps from https://fedoraproject.org/wiki/Features/InitialExperience#How_To_Test don't work.
Looks good, thanks for the update! A minor suggestion: perhaps rather than "click the 'Start using GNOME 3' button," we could write "choose 'Start using GNOME 3,'" which allows for any input method, and eliminates extra words. We should still wait for comments from the assigned QA contact.