Microsoft® Visual Studio® 2005 Service Pack 1 is now available as a download from MSDN.
Go to: http://www.microsoft.com/downloads/details.aspx?familyid=BB4A75AB-E2D4-4C96-B39D-37BAF6B5B1DC&mg_id=10055&displaylang=en
Service Pack 1 also provides over 70 improvements for common development scenarios including:
The complete release notes can be found at http://support.microsoft.com/default.aspx/kb/928957/.
As it turns out, it's pretty unclear what has been fixed in this service pack. The 'What's New in Visual Studio 2005 SP1' page doesn't provide any information. Back in September Somasegar promised to provide a list of fixes, but in his post about the release of SP1 he makes no mention of what has been fixed.
Update: a list of fixes in Visual Studio 2005 SP1 can be found at: http://support.microsoft.com/kb/918526/en-us