Microsoft previously announced a push-back before the US holiday season, and the addition of a Release Candidate in February 2010.

“In order to ensure that we are able to receive and react to this feedback, we will also be moving the launch of Visual Studio 2010 and .NET 4 back a few weeks.”

Since the RC hasn’t happened yet and the “receive and react to” window is a fixed length of time, it makes me believe that Microsoft is now confident enough about its solution to the performance issues that it can announce a final date with at least the perception of a reaction to the added RC.