You can use WPF animation effects to customize Tabs Studio presentation. Tabs Studio v1.7.3 demonstrates fade effect for the yellow extension background when mouse is over it and transition effect between states for the close tab button. You can turn on these two effects in the Quick Style window:

Quick Style animate option
For example, fade-in effect for an extension starts on mouse enter event, during 0.2 seconds it changes border color from transparent to gray and it changes yellow background from transparent to opaque:
<EventTrigger RoutedEvent="Control.MouseEnter">
<EventTrigger.Actions>
<BeginStoryboard>
<Storyboard>
<ColorAnimation Duration="0:0:0.2" Storyboard.TargetName="Border" Storyboard.TargetProperty="BorderBrush.Color" To="Gray"/>
<DoubleAnimation Duration="0:0:0.2" Storyboard.TargetName="LabelText" Storyboard.TargetProperty="Background.Opacity" To="1"/>
</Storyboard>
</BeginStoryboard>
</EventTrigger.Actions>
</EventTrigger>
Full sample effects definitions are available when you turn on animation and generate style in the Quick Style window. I think the most common customization for the sample effects provided will be adjustment of animation duration.
Tabs Studio v1.7.3 is released – added a Quick Style option to animate extension selection and the close tab button, improved selected tab glow in Visual Studio 2010, fixed excessive selected tab updates.
I’ve updated default TabExtension style to ease extension selection. When mouse is over extension it is highlighted with yellow background now, there is no more shadow for extension and there is more padding around tab extension and tab name:

Updated tab extension style
Tabs Studio v1.7.1 is released – added Visual Studio 2010 Beta 2 support, added automatic registration with SQL Server Management Studio 2005.
WPF 4.0 introduces new text rendering options. You can customize Tabs Studio text with these new options in Visual Studio 2010 Beta 2 using a style like this one:
<Style TargetType="TabsStudio:Tabs" BasedOn="{StaticResource DefaultTabsStyle}">
<Setter Property="TextOptions.TextFormattingMode" Value="Display"/>
<Setter Property="TextOptions.TextRenderingMode" Value="Aliased"/>
</Style>

Text with display aliased options

Text with display aliased options 3x zoom
It would be great to make sharper text works in Visual Studio 2008 as well, but right now I don’t see a good solution. Simply installing .NET 4.0 Beta 2 runtime on a Visual Studio 2008 machine doesn’t make these new options available to Tabs Studio automatically.
Visual Studio 2010 Beta 2 was released this week. The only change I see (comparing to VS window tabs management in 2010 Beta 1) is the new Insert documents to the right of existing tabs option that allows opening tabs on the right:

Insert documents to the right option
I’ve updated Tabs Studio to accommodate some Visual Studio 2010 Beta 2 internal changes and I will make it available in the next release:

Tabs Studio in Visual Studio 2010 Beta 2
As VS 2010 release date is set to March 22, 2010, I’ve extended evaluation period for Tabs Studio 2010 to April 22, 2010.
Tabs Studio v1.6.5 is released – redesigned close tab button, added Quick Style builder, added Help link to Options and Add-in Manager, added automatic registration with SSMS, conducted general UI cleanup.
I’ve added Tabs Studio registration with SQL Server Management Studio 2008 to the Tabs Studio installer. There will be no need to manually setup and run the .reg file any more.