If you haven’t heard already, Microsoft announced that Visual Studio 2010 Release Candidate was available for MSDN subscribers and would be probably available on 10 February 2010 for the public, which is today.  But before you get all excited and start installing the latest and greatest as soon as possible, you might want to slow down and reconsider; at least if you are a Silverlight developer.

Here are my two reasons for waiting:

• At this time, VS2010 RC does not support developing Silverlight 4 applications.  This means that at this time there is no update for Silverlight 4 runtime/tools or the WCF RIA Services or other companion frameworks (toolkit controls, etc.).  This will not be enabled until the next public build of Silverlight 4 and companion frameworks.
• Visual Studio 2010 Beta 2 and Visual Studio RC does NOT install side-by-side. You must first uninstall VS Beta 2 then install VS2010 RC.

So, if you want to keep developing on Silverlight 4, stick with the VS Beta 2 for now. At least until the next public build Silverlight 4 is released.

Brian Lagunas Silverlight silverlight 4 beta