How to implement INotifyDataErrorInfo in WPF 4.5?

Beside the very detailed description on MSDN about the Silverlight version of INotifyDataErrorInfo

There are already some blog posts with samples how to use/implement it in WPF 4.5:

• WPF 4.5 – Asynchronous validation (original link no longer working) Wayback Link
• WPF 4.5 – Part 1 : Asynchronous data validation (the author has a nice series about the new fetaures in WPF 4.5)