Task Parallel Library (TPL) in .NET 4.0

Untill now, I have written about major enhancements to C# 4.0. Today, I want to talk about what is coming with the .NET Framework 4.0. There are a lot of new things coming with .NET 4.0, WPF 4.0, WCF 4.0, WF 4.0, Code Contracts to name a few. But for the matter of this post, I would like to throw light on the Task Parallel Library (TPL from now on, to save me typing).
TPL is the enhancement to the .NET Framework to make concurrent programming on multi core systems easier. We had an option previously to write parallel programs, Threads, but it was "expensive" and difficult. With "expensive", I mean, you have to create a thread object and it incurs system overhead. And by "difficult", I mean, it is very difficult to synchronize access to shared resources and finding dead locks etc.

The .NET Framework 4.0 provides another "high-level" layer on top of the stack to make our lives easier. Now, we don't need to create "Thread" ourselves. We only create a Task (class), and pass in the delegate or method to execute. The underlying framework determines itself either to create a thread or not for the particular task or to assign it to already executing task. Before I go into the details about the TPL, I would like you to read this post by Daniel moth.
In which he describes the "major over hauling" of ThreadPool in .NET 4.0.