gistfile1.txt

<Window x:Class="WpfApplication4.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        Title="MainWindow" Height="350" Width="525">
    <Grid>

        <Grid.Resources>

            <Style x:Key="HiddenTabItem" TargetType="{x:Type TabItem}">
                <!--<Setter Property="Visibility" Value="Visible"/>-->
                <Setter Property="Template">
                    <Setter.Value>
                        <ControlTemplate TargetType="{x:Type TabItem}">

                            <Border x:Name="TabHeader" BorderThickness="1,1,0,1" Background="{TemplateBinding Background}" BorderBrush="{TemplateBinding BorderBrush}" Padding="{TemplateBinding Padding}">
                                <ContentPresenter SnapsToDevicePixels="{TemplateBinding SnapsToDevicePixels}" HorizontalAlignment="{Binding Path=HorizontalContentAlignment, RelativeSource={RelativeSource AncestorType={x:Type ItemsControl}}}" VerticalAlignment="{Binding Path=VerticalContentAlignment, RelativeSource={RelativeSource AncestorType={x:Type ItemsControl}}}" ContentSource="Header" RecognizesAccessKey="True"/>
                            </Border>

                            <ControlTemplate.Triggers>
                                <Trigger SourceName="TabHeader" Property="IsMouseOver" Value="True">
                                    <Setter Property="Visibility" Value="Hidden" />
                                </Trigger>
                            </ControlTemplate.Triggers>
                        </ControlTemplate>
                    </Setter.Value>
                </Setter>
            </Style>

        </Grid.Resources>

        <TabControl>
            
            <TabItem Style="{StaticResource HiddenTabItem}" Header="Woo"></TabItem>
            <TabItem Style="{StaticResource HiddenTabItem}" Header="Woo2"></TabItem>
            <TabItem Style="{StaticResource HiddenTabItem}" Header="Woo3"></TabItem>
            
        </TabControl>
        
    </Grid>
</Window>