For those of you who are wondering about compatibility issues between Microsoft's XNA Game Studio Express and Windows Vista, we've come across some interesting - and official - info courtesy of Michael Klucher, the Program Manager for XNA Game Studio.

According to Klucher, XNA Game Studio Express by Microsoft">XNA Game Studio Express is tightly integrated with Visual C# 2005 Express Edition.

That means XNA Game Studio Express is "highly reliant on the features and capabilities of Visual C# Express and, more generally, Visual Studio 2005." Anyway, here's the full explanation straight from Klucher himself:

Visual C# Express is supported on Windows Vista if both the Visual Studio 2005 Service Pack 1 (SP1) and the Visual Studio 2005 SP1 Update for Windows Vista are applied. Currently SP1 is in Beta and the SP1 Update is under development. XNA Game Studio Express relies heavily on Visual C# Express and will need both of these updates in order to have full functionality on Windows Vista.