Very little has changed in tabs behavior since the developer preview (see my older blog post Document tabs in Visual Studio 11 Developer Preview), but the UI theme is all new:
Plus there is also the dark theme:
One more color change is for the scenario when you have several tab groups or floating document windows. In Visual Studio 2010, selected but inactive document tab had two states: last active document group or not. See how in the following screenshot MainWindow.xaml.vb is gray and its tab group has gray underline (MainWindow.xaml.vb was the selected document before I switched to Solution Exlorer), Application.xaml.vb is almost transparent and its tab group has corresponding underline:
In Visual Studio 11 Beta there is no such distinction. All inactive tab groups are just grey:
I’ve not found significant changes in VS 11 tabs customization comparing to the developer preview:
Remember Visual Studio 2010 Beta release when Microsoft introduced WPF UI? This beta again completely changed VS look and feel. Let’s see whether customers’ feedback to add some color back to Visual Studio 11 prompts Microsoft to reconsider the latest design.