Estoy tratando de crear una experiencia similar a la de ScrollViewerSample desde las muestras del SDK de Windows 8 para poder ajustar los elementos dentro de un ScrollViewer cuando se desplaza hacia la izquierda y hacia la derecha. La implementación de la muestra (que funciona) es así:

<code><ScrollViewer x:Name="scrollViewer" Width="480" Height="270"
              HorizontalAlignment="Left" VerticalAlignment="Top"
              VerticalScrollBarVisibility="Disabled" HorizontalScrollBarVisibility="Auto" 
              ZoomMode="Disabled" HorizontalSnapPointsType="Mandatory">
    <StackPanel Orientation="Horizontal">
        <Image Width="480" Height="270" AutomationProperties.Name="Image of a cliff" Source="images/cliff.jpg" Stretch="None"  HorizontalAlignment="Left" VerticalAlignment="Top"/>
        <Image Width="480" Height="270" AutomationProperties.Name="Image of Grapes" Source="images/grapes.jpg" Stretch="None" HorizontalAlignment="Left" VerticalAlignment="Top"/>
        <Image Width="480" Height="270" AutomationProperties.Name="Image of Mount Rainier" Source="images/Rainier.jpg" Stretch="None" HorizontalAlignment="Left" VerticalAlignment="Top"/>
        <Image Width="480" Height="270" AutomationProperties.Name="Image of a sunset" Source="images/sunset.jpg" Stretch="None" HorizontalAlignment="Left" VerticalAlignment="Top"/>
        <Image Width="480" Height="270" AutomationProperties.Name="Image of a valley" Source="images/valley.jpg" Stretch="None" HorizontalAlignment="Left" VerticalAlignment="Top"/>
    </StackPanel>
</ScrollViewer>
</code>

La única diferencia con mi implementación deseada es que no quiero un StackPanel con elementos dentro, sino algo a lo que pueda enlazar. Estoy tratando de lograr esto con un ItemsControl, pero por alguna razón el comportamiento Snap no se activa:

<code><ScrollViewer x:Name="scrollViewer" Width="480" Height="270"
              HorizontalAlignment="Left" VerticalAlignment="Top"
              VerticalScrollBarVisibility="Disabled" HorizontalScrollBarVisibility="Auto" 
              ZoomMode="Disabled" HorizontalSnapPointsType="Mandatory">
    <ItemsControl>
        <ItemsControl.ItemsPanel>
            <ItemsPanelTemplate>
                <StackPanel Orientation="Horizontal" />
            </ItemsPanelTemplate>
        </ItemsControl.ItemsPanel>
        <Image Width="480" Height="270" AutomationProperties.Name="Image of a cliff" Source="images/cliff.jpg" Stretch="None"  HorizontalAlignment="Left" VerticalAlignment="Top"/>
        <Image Width="480" Height="270" AutomationProperties.Name="Image of Grapes" Source="images/grapes.jpg" Stretch="None" HorizontalAlignment="Left" VerticalAlignment="Top"/>
        <Image Width="480" Height="270" AutomationProperties.Name="Image of Mount Rainier" Source="images/Rainier.jpg" Stretch="None" HorizontalAlignment="Left" VerticalAlignment="Top"/>
        <Image Width="480" Height="270" AutomationProperties.Name="Image of a sunset" Source="images/sunset.jpg" Stretch="None" HorizontalAlignment="Left" VerticalAlignment="Top"/>
        <Image Width="480" Height="270" AutomationProperties.Name="Image of a valley" Source="images/valley.jpg" Stretch="None" HorizontalAlignment="Left" VerticalAlignment="Top"/>
    </ItemsControl>
</ScrollViewer>
</code>

¡Las sugerencias serían apreciadas grandemente!

Gracias a Denis, terminé usando el siguiente estilo en ItemsControl y eliminé ScrollViewer y los elementos en línea ItemsPanelTemplate por completo:

<code><Style x:Key="ItemsControlStyle" TargetType="ItemsControl">
    <Setter Property="ItemsPanel">
        <Setter.Value>
            <ItemsPanelTemplate>
                <VirtualizingStackPanel Orientation="Horizontal"/>
            </ItemsPanelTemplate>
        </Setter.Value>
    </Setter>
    <Setter Property="Template">
        <Setter.Value>
            <ControlTemplate TargetType="ItemsControl">
                <ScrollViewer Style="{StaticResource HorizontalScrollViewerStyle}" HorizontalSnapPointsType="Mandatory">
                    <ItemsPresenter />
                </ScrollViewer>
            </ControlTemplate>
        </Setter.Value>
    </Setter>
</Style>
</code>