I am a little late in the news but it has finally happened. Little off the May release date, oh well.
I have not gotten into the new things going on with 3.1 yet but certainly will and get back to you all on what I find and some new tutorials demonstrating some of the new features.
Here is the link to XNA Game Studio 3.1
I have not seen it before so I apologize if I have missed it previously, but MS has also added a new quick start guide you can find here.
Happy XNA'g everyone!