Multithreading improvements in .NET 4

Question

I have heard that the .NET 4 team has added new classes in the framework that make working with threads better and easier.

Basically the question is what are the new

Answer 1

Strictly speaking this is C# 4.0 and not a new class, but events now have a smarter form of locking which if I've understood the change correctly, removes the need for reems of locking code as shown below (taken from this article by Jon Skeet):

SomeEventHandler someEvent;
readonly object someEventLock = new object();

public event SomeEventHandler SomeEvent
{
    add
    {
        lock (someEventLock)
        {
            someEvent += value;
        }
    }
    remove
    {
        lock (someEventLock)
        {
            someEvent -= value;
        }
    }
}