Some of of the advancements in Service Pack 1 for Visual Studio 2005 which is available for download:

• “New processor support (e.g., Core Duo) for code generation and profiling”
• “Performance and scale improvements in Team Foundation Server”
• “Team Foundation Server integration with Excel 2007 and Project 2007”
• “Tool support for occasionally connected devices and SQL Server Compact Edition”
• “Additional support for project file based Web applications”
• “Windows Embedded 6.0 platform and tools support”

Especially the Core Duo support sound quite nifty to me. However, running Vista you have to wait some more weeks for some additional features.

“For developers using Visual Studio 2005 on Windows Vista, Microsoft is in current development on an update to Service Pack 1 called the ‘Visual Studio 2005 SP1 Vista Refresh Beta’. This update builds on the improvements made in SP1 and delivers a first class experience for developers wanting to take advantages of the new features in Windows Vista. The Visual Studio 2005 SP1 Update for Windows Vista is expected to ship after the consumer availability of Windows Vista in Q1 of 2007 and is now available in bet”

Just in case you are wondering why the two service packs are separated you can find more over here.