Анимация в XAML

Для страждущих.

<Window
 xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
 xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
 x:Class="WpfEx.MainWindow"
 x:Name="Window"
 Title="MainWindow"
 Width="640" Height="480">
 <Window.Resources>
  <Storyboard x:Key="OnLoadedLeft">
   <DoubleAnimationUsingKeyFrames AutoReverse="True" 
                                  RepeatBehavior="Forever" 
                                  BeginTime="00:00:00"
                                  Storyboard.TargetName="ellipse"            
                                  Storyboard.TargetProperty="(Canvas.Left)">
    <SplineDoubleKeyFrame KeyTime="00:00:00" Value="0"/>
    <SplineDoubleKeyFrame KeyTime="00:00:03" Value="400"/>
   </DoubleAnimationUsingKeyFrames>
  </Storyboard>
     <Storyboard x:Key="OnLoadedTop">
   <DoubleAnimationUsingKeyFrames AutoReverse="True" 
                                  RepeatBehavior="Forever"
                                  BeginTime="00:00:00"
                                  Storyboard.TargetName="ellipse"
                                  Storyboard.TargetProperty="(Canvas.Top)">
    <SplineDoubleKeyFrame KeyTime="00:00:00" Value="0"/>
    <SplineDoubleKeyFrame KeyTime="00:00:03.5" Value="300"/>
   </DoubleAnimationUsingKeyFrames>
  </Storyboard>
 </Window.Resources>
 <Window.Triggers>
  <EventTrigger RoutedEvent="FrameworkElement.Loaded">
   <BeginStoryboard Storyboard="{StaticResource OnLoadedLeft}"/>
  </EventTrigger>
    <EventTrigger RoutedEvent="FrameworkElement.Loaded">
   <BeginStoryboard Storyboard="{StaticResource OnLoadedTop}"/>
  </EventTrigger>
 </Window.Triggers>

 <Canvas>
  <Ellipse x:Name="ellipse" 
           Fill="#FF1A19E8" 
           Stroke="Black"
           Width="50"
           Height="50"
           Canvas.Left="0"
           Canvas.Top="0"
           StrokeThickness="0"/>
 </Canvas>
</Window>