Anything you've archived may be restored. All restored content is brought back in draft, so be sure to republish.
From the Site Center, click the Tools tab, and then the View List button for undeleting pages and minisites.
On the next page, check the box next to the item you wish to restore before clicking the Undelete button.
Alternately, you may follow the same instructions from a Minisite Center. In that case, you'll only see the list items archived from that Minisite whereas the the Site Center allows you to restore anything archived from anywhere on the site.