Microsoft Expression Blend 2.0 is not compatible with Visual Studio 8. When you try to edit your XAML page in Expression Blend, there are some errors saying that XAML page is not valid.
The solution is simple, you have to download and install Microsoft Expression Blend 2.5 June Preview. After installation, don't forget to run it once.
This should resolve the compability issue between Visual Studio and Expression Blend.
