Blend tends to create its XAML in very long lines.
Is there a way to reformat it so that the properties of each element are lined up vertically under each other?
You can do it by using Visual Studio:
Change the default settings for XAML documents, and then use CTRL+E,D (Edit | Advanced | Format Document) or CTRL+E,F (Edit | Advanced | Format Selection).
http://weblogs.asp.net/fmarguerie/archive/2008/06/07/xaml-markup-formatting-in-visual-studio.aspx