Sean Daniel has just posted a really good article on his blog called Announcing Windows Storage Server 2008 R2 Essentials and in it he compares some of the differences between Home Server Vail, Windows Storage Server 2008 R2 Essentials and Small Business Server 2011 Essentials.
Today Microsoft announced Windows Storage Server 2008 R2 Essentials – also known as Breckenridge – and it shares common features with both Windows Home Server Vail and Windows Small Business Server 2011 Essentials.