Here is a compilation of very useful utilities for VS 2010 and VS 11.
Note: Utilities with an asterisk (*) beside the name are not available to VS 11 yet.
CLIArgs Made Easy
CLI Args Made Easy (Command Line Arguments Made Easy) is an add-in that allow you to change the command line arguments of the startup project very easily by adding a combobox in the toolbar. It also saves all the arguments you insert for future use.
Debugger Canvas (*)
Debugger Canvas is a new user experience for the debugger in Visual Studio Ultimate. It pulls together the code you’re exploring onto a single pan-and-zoom display. Visual debugger and multithreading debugging goodies.
Productivity Power Tools (*)
A set of extensions to Visual Studio Professional (and above) which improves developer productivity. Very useful enhanced scrollbar, vertical tabs, quick find files, searchable references and editing tools.
Visual Assist X
Mercurial Source Control Plugin for MS Visual Studio.