In case you haven't seen the announcements, the CTP of SQL Server 2005 SP1 is now available for download. This also includes updates to the community pack (ADMOMD.net, DTS Designer, SNAC, AS OLE DB Provider, etc.) and books online.
The Express stuff is really exciting. Take a look at this:
SQL Server Express Edition with SP1 (SQLEXPR.EXE)
SQL Server 2005 Express Edition (SQL Server Express) is a powerful and reliable data management product that delivers rich features, data protection, and performance for embedded application clients, light Web applications, and local data stores. Designed for easy deployment and rapid prototyping, SQL Server Express is available at no cost, and you are free to redistribute it with applications. If you need more advanced database features, then SQL Server Express can be seamlessly upgraded to more sophisticated versions of SQL Server.
SQL Server Express Edition with Advanced Services (SQLEXPR_ADV.EXE)
SQL Server 2005 Express Edition with Advanced Services is a new, free version of SQL Server Express that includes additional features for reporting and advanced text based searches. In addition to the features offered in SQL Server 2005 Express Edition, SQL Server Express with Advanced Services offers additional components that include SQL Server Management Studio Express (SSMSE), support for full-text catalogs, and support for viewing reports via report server. SQL Server Express Edition with Advanced Services also includes SP1.
SQL Server Express Edition Toolkit (SQLEXPR_TOOLKIT.EXE)
SQL Server 2005 Express Edition Toolkit (SQL Server Express Toolkit) provides tools and resources to manage SQL Server Express and SQL Server Express Edition with Advanced Services. It also allows creating reports by using SQL Server 2005 Reporting Services (SSRS).
SQL Server Management Studio Express (SQLServer2005_SSMSEE.msi)
SQL Server Management Studio Express (SSMSE) provides a graphical management tool for managing SQL Server 2005 Express Edition and SQL Server 2005 Express Edition with Advanced Services instances. SSMSE can also manage relational engine instances created by any edition of SQL Server 2005. SSMSE cannot manage Analysis Services, Integration Services, SQL Server 2005 Mobile Edition, Notification Services, Reporting Services, or SQL Server Agent.