Recognize that Feb 27, 2008 is the "Launch Date".  The release date is not the same as the "Launch Date".  That only means there will be big events, satellite broadcasts, and boxes in stores on that date. 

Visual Studio will still be "released" by end of the year: http://blogs.msdn.com/dseven/archive/2007/07/10/windows-server-2008-visual-studio-2008-and-microsoft-sql-server-2008-joint-launch-announced.aspx

SQL Server 2008 is still planned for a "2Q 2008" release (that would be after the "Launch date"): http://blogs.msdn.com/dtjones/archive/2007/07/10/sql-server-2008-to-launch-on-2-27-2008.aspx