In addition to providing support for SQL Server 2008 database projects, this release incorporates many previously released Power Tools as well as several new features. The new features include distinct Build and Deploy phases, Static Code Analysis and improved integration with SQL CLR projects. Database Edition no longer requires a Design Database. Therefore, it is no longer necessary to install an instance of SQL Express or SQL Server prior to using Database Edition.
Abstract courtesy : Microsoft
Reference : Pinal Dave (http://blog.SQLAuthority.com)