A great posting over on the project blog about the changes to how assignment units are used and displayed in Project 2010.  This was a feature change that makes total sense once you understand the reasoning behind it – but on first glance is a major difference from the world of Project we all know and love.  This was the right change for the right reasons – and we get a red man too!  Read on at http://blogs.msdn.com/project/archive/2010/04/29/assignment-units-in-project-2010.aspx