Similar to Jira's System Dashboard (pictured below), it would be great if Confluence Data Center offered a similar landing page that allowed for a system welcome message and login prompts. 

We offer this concept today through the Confluence Dashboard BUT you need to enable Anonymous Access via Confluence's Global Permissions to view it without logging in.  For any customer that has strict mandates to disable anonymous access, they lose the ability to offer a landing page and welcome message for non-authenticated users. 

Also note that lack of a landing page for non-anonymous sites limits options for customers that implement SAML SSO and need to specify a workable logout redirection URL.