Today Visual Studio 2008 SP1 and the .NET Framework 3.5 SP1 have been released to web and are available from the download centre:

The .NET Framework 3.5 SP1 includes a lot of improvements and especially TONS (literally tons) of performance improvements for WPF applications, ADO.NET Entity Framework, ASP.NET Dynamic Data, ADO.NET Data Services Framework and much more…

PLEASE NOTE: If develop Silverlight apps with Visual Studio, please note that after installing Visual Studio 2008 SP1 you must update the Silverlight Tools (more info and download links are available here).

Update: Also Visual Studio Team System SP1 is now available here