According to Microsoft Product Manager of Visual Studio Mr. Scott Guthrie, Visual Studio 2010 Release Candidate might come out on Feb 2010, with more improved memory management functionality.
In order to make sure that these fixes truly address the performance issues reported, and to help validate them across the broadest number of scenarios and machine configurations, we’ve decided to ship another public preview release of VS 2010 and .NET 4 before we ship. Specifically, we plan to make a Release Candidate build available in February that everyone will be able to download and test. It will be a public build and include a broad “go live” license that supports production deployment.
Read more in ScottGu’s Blog @ VISIT LINK