Traditional debuggers show you the state of your application at the current time with limited information about events that occurred in the past. With IntelliTrace, you can actually see events that occurred in the past and the context in which they occurred. this reduces the number of restarts that are required to debug your application and the possibility that an error will fail to reproduce when you return the application.

IntelliTrace operates invisibly in the background, recording debug information. when you want to look back at a past state of your application, you can enter IntelliTrace mode. In this mode, you can navigate to various points in time where events of interest have been recorded.

when you use the default settings, IntelliTrace has minimal effect on application performance. Therefore, IntelliTrace is turned on by default. even if you did not plan to use IntelliTrace when you started your

IntelliTrace can save time by shortening the debugging cycle. For example, suppose that you are debugging an application that reads a registry value during initialization, but the registry key does not exist. The effect of that problem might not be noticeable until much later in the run of your application. Then, you must determine why the registry value was not read. The usual approach is to restart the application and place a breakpoint near the registry access. Rerunning the application takes time. With IntelliTrace, you can avoid many such restarts. Instead of rerunning your application, you can begin debugging with IntelliTrace, which enables you to look back at all registry accesses, choose the one that interests you, and examine the state of your application when that registry access occurred. You might experience similar time savings when you debug other problems such as an exception or a file access error.

you can watch this links

IntelliTrace in Visual Studio 2010 and Team Foundation Server 2010 | IntelliTrace Debugging in Visual Studio 2010 | How Do I: Using IntelliTrace in Visual Studio 2010

My References:

Debugging Applications with IntelliTrace | IntelliTrace: A graphical comparison | Debuggin LINQ to SQL queries using the Hisorical Debugger | Fix Bugs Faster with IntelliTrace 2010