Here is a little something something for you all looking to do gradiant borders. This may not fit everyones taste but you can use it to partially what you are looking for.

I personally am using this XAML as a backdrop template for my Silverlight apps, when doing stuff like Login overlays, or ad-hoc data entry that requires immediate information input.

Since the XAML framework is not really designed (when doing custom displays as such) for clean formatting, but verry good at detailing specific layouts if you know what you are looking for.

<Grid x:Name="LayoutRoot" Cursor="Hand">
  <Grid.RowDefinitions>
    <RowDefinition Height="50" />
    <RowDefinition Height="150" />
    <RowDefinition Height="50" />
  </Grid.RowDefinitions>
  <Grid.ColumnDefinitions>
    <ColumnDefinition Width="50" />
    <ColumnDefinition Width="150" />
    <ColumnDefinition Width="50" />
  </Grid.ColumnDefinitions>
  <Border Grid.Row="0" Grid.Column="0" CornerRadius="10,0,0,0" >
    <Border.Background>
      <RadialGradientBrush Center="1,1" RadiusX="1" RadiusY="1" GradientOrigin="1,1">
        <GradientStop Color="silver" Offset="0.5" />
        <GradientStop Color="Transparent"  Offset=".98"/>
      </RadialGradientBrush>
    </Border.Background>
  </Border>
  <Border Grid.Row="2" Grid.Column="0" CornerRadius="0,0,10,0">
    <Border.Background>
      <RadialGradientBrush Center="1,0" RadiusX="1" RadiusY="1" GradientOrigin="1,0">
        <GradientStop Color="Silver" Offset=".5" />
        <GradientStop Color="Transparent" Offset=".98" />
      </RadialGradientBrush>
    </Border.Background>
  </Border>
  <Border Grid.Row="0" Grid.Column="2" CornerRadius="0,10,0,0">
    <Border.Background>
      <RadialGradientBrush Center="0,1" RadiusX="1" RadiusY="1" GradientOrigin="0,1">
        <GradientStop Color="Silver" Offset=".5" />
        <GradientStop Color="Transparent" Offset=".98" />
      </RadialGradientBrush>
    </Border.Background>
  </Border>
  <Border Grid.Row="2" Grid.Column="2" CornerRadius="0,0,0,10">
    <Border.Background>
      <RadialGradientBrush Center="0,0" RadiusX="1" RadiusY="1" GradientOrigin="0,0">
        <GradientStop Color="Silver" Offset=".5" />
        <GradientStop Color="Transparent" Offset=".98" />
      </RadialGradientBrush>
    </Border.Background>
  </Border>
  <Border Grid.Row="1" Grid.Column="0">
    <Border.Background>
      <LinearGradientBrush StartPoint="0,0" EndPoint="1,0">
        <GradientStop Color="Transparent" Offset="0" />
        <GradientStop Color="Silver" Offset=".5"/>
      </LinearGradientBrush>
    </Border.Background>
  </Border>
  <Border Grid.Row="0" Grid.Column="1">
    <Border.Background>
      <LinearGradientBrush StartPoint="0,0" EndPoint="0,1">
        <GradientStop Color="Transparent" Offset="0" />
        <GradientStop Color="Silver" Offset=".5" />
      </LinearGradientBrush>
    </Border.Background>
  </Border>
  <Border Grid.Row="1" Grid.Column="2">
    <Border.Background>
      <LinearGradientBrush StartPoint="1,1" EndPoint="0,1">
        <GradientStop Color="Transparent" Offset="0" />
        <GradientStop Color="Silver" Offset=".5" />
      </LinearGradientBrush>
    </Border.Background>
  </Border>
  <Border Grid.Row="2" Grid.Column="1">
    <Border.Background>
      <LinearGradientBrush StartPoint="1,1" EndPoint="1,0">
        <GradientStop Color="Transparent" Offset="0" />
        <GradientStop Color="Silver" Offset=".5" />
      </LinearGradientBrush>
    </Border.Background>
  </Border>
  <Canvas Grid.Row="1" Grid.Column="1" Background="Silver" />
</Grid>