Why are XML DataTemplates ignored.

In the following sample, the DataTemplate is ignored by WPF.

Why is this?

    <Window x:Class="TestXmlNonBinding.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" xmlns:Xml="clr-namespace:System.Xml;assembly=System.Xml">
    <Window.Resources>
        <DataTemplate DataType="{x:Type Xml:XmlDocument}">
            <TextBlock>Hello</TextBlock>
        </DataTemplate>
    </Window.Resources>
    <Window.DataContext>
        <Xml:XmlDocument></Xml:XmlDocument>
    </Window.DataContext>
    <Grid>
        <ContentControl Content="{Binding}"></ContentControl>
    </Grid>
</Window>

Why are XML DataTemplates ignored.
===


In the following sample, the DataTemplate is ignored by WPF.

Why is this?

    <Window x:Class="TestXmlNonBinding.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" xmlns:Xml="clr-namespace:System.Xml;assembly=System.Xml">
    <Window.Resources>
        <DataTemplate DataType="{x:Type Xml:XmlDocument}">
            <TextBlock>Hello</TextBlock>
        </DataTemplate>
    </Window.Resources>
    <Window.DataContext>
        <Xml:XmlDocument></Xml:XmlDocument>
    </Window.DataContext>
    <Grid>
        <ContentControl Content="{Binding}"></ContentControl>
    </Grid>
</Window>
