SharePoint Designer 2010 will not allow non SharePoint Sites!!!

 SharePoint Designer 2007 allowed you to build and maintain a non-SharePoint site. In the 2010 version of SharePoint Designer you no longer have that option. In fact, SharePoint Designer 2010 will only connect to a SharePoint Server 2010 server.So, if you are developing with SharePoint you use SharePoint Designer. If you are doing just general disk based web-sites, you switch over to Expression Web.