.NET 4.0 and System.Threading.Tasks
In the soon-to-be-released .NET 4.0 framework and Visual Studio 2010 we are going to get a plethora of new tools to help us write better multi-threaded applications. One of these tools is a new namespace within the System.Threading namespace which is called "Tasks". The Tasks in System.Threading.Tasks namespace are a method of fine grained parallelism, similar to creating and using threads, but they have a few key differences.
via codethinked.com
Good intro. The Task library seems to be fluent and very lambda friendly.
Apparently, there's a new threadpool in .NET 4. I never did like the old ThreadPool class.