Shared pages and templates is currently not supported. So this could be done if you have two installations and App_Data/Sitefinity/WebsiteTemplates is shared folder and you use custom templates and themes. In this case the pages and all data will be different. The common thing is that you will use the same physical templates and themes, but you will not be able to sync the controls added in both the instances you will install.
We are going to have similar scenario after Q2 release - mapping page nodes to a domain name/subdomain that will allow you to "split" the SiteMap between several hosts.
the Telerik team