With .NET 4.0 Microsoft will bring up a improved version of XAML. This arcitle shows you the language enhancements they made.
Easy Object References with {x:Reference}
If you want to create an object reference today you need to do a databinding and declare the source with an ElementName. In XAML 2009 you can use the new {x:Reference} markup extension
<!-- XAML 2006 -->
<Label Target="{Binding ElementName=firstName}">FirstName</Label>
<TextBox x:Name="firstName" />
<!-- XAML 2009 -->
<Label Target="{x:Reference firstName}">FirstName</Label>
<TextBox x:Name="firstName" />
<Label Target="{Binding ElementName=firstName}">FirstName</Label>
<TextBox x:Name="firstName" />
<!-- XAML 2009 -->
<Label Target="{x:Reference firstName}">FirstName</Label>
<TextBox x:Name="firstName" />