The initial RTM build of Visual Studio 2010 was released in early April this year. It is a radical improvement compared to the previous releases of Visual Studio and it introduced many improvements to the existing development areas, like WPF and Silverlight. However, it was time that some additional improvements and additions were introduced, so Microsoft announced the availability of the first Service Pack for Visual Studio 2010, which is currently in the beta stage.
Since in this article I am talking about beta software, I do not recommend installing it on a production machine (the same principle applied to any beta software). You should also remember that the current release might not be always stable and might contain errors. You are encouraged to report those on the Microsoft Connect website. That being said, however, here is what's stated on the official Visual Studio Product Feedback blog:
Beta will be supported as a “go live” release. This means that this software has met high standards of quality for a pre-release, and we are licensing it for developing and deploying production applications.
This, however, doesn't mean that the beta is as reliable as the RTM release, so:
You should take adequate measures to back up and protect your data prior to installing the beta. You should also have an ongoing data backup and protection plan in place during your use of this prerelease.
You can download the service pack here (as a web installer) or here (as an ISO). The download size is estimated to 503MB for the web installer and 593MB for the ISO, so get ready to wait a little bit while it gets on your computer.
In this service pack, several improvements were introduced for Silverlight and web developers. Among other good stuff, you can now use the Performance Wizard in the context of Silverlight projects. And there is a new and improved Help Viewer (version 1.1):
It is more lightweight, faster and optimized for tabbed navigation. The help content no longer opens in a browser, however it still relies on the Help Agent, so all content can be accessed via browser if you want to.
For some more details on what Service Pack 1 brings to the table, I would recommend visiting these resources: