Extreme Project Management [1] is described as the PM part of Extreme Programming - in my point of view the vertical, functional slicing of a project is inherent to XP (Extreme Programming) and is documented / explained well already in my own articles' links [2] as well as resources like the XP-Faq [3] or the 1000+ messages per month high volume XP mailing list [4] ...
So the term Extreme Project Management actually only refers to the ideas of XP in general... nothing new at all.