Thanks to Josh Blake, I came across a good article by Charles Petzold  in the September 2010 issue of MSDN Magazine:
Touch and Response


In this article,  Charles Petzold continues his discussion of the multi-touch support in version 4 of Windows Presentation Foundation (WPF).  I like the introduction to his article:
"Programming is an engineering discipline rather than a science or a branch of mathematics, so rarely does there exist a single correct solution to a problem. Varieties and variations are the norm, and often it’s illuminating to explore these alternatives rather than focus on one particular approach." -Charles Petzold
I also appreciate Petzold's discussion about smooth Z transitions, his thoughtful code samples and related links.

RELATED
Multi-touch Manipulation in WPF 
Charles Petzold (August, 2010, MSDN Magazine, UI Frontiers)
"Just within the past few years, multi-touch has progressed from a futuristic sci-fi film prop to a mainstream UI. Multi-touch displays are now standard on new models of smartphones and tablet computers. Multi-touch is also likely to become ubiquitous on computers in public spaces, such as kiosks or the table computer pioneered by Microsoft Surface."
"The only real uncertainly is the popularity of multi-touch on the conventional desktop computer. Perhaps the greatest impediment is the fatigue known as “gorilla arm” associated with moving fingers on vertical screens for long periods of time. My personal hope is that the power of multi-touch will actually provoke a redesign of the desktop display. I can envision a desktop computer with a display resembling the configuration of a drafting table, and perhaps almost as large." -Charles PetzoldExploring Multi-Touch Support in Silverlight
Charles Petzold (March 2010, MSDN Magazine, Finger Style)


Comment:
I agree with Charles about the need for a re-design of desktop displays.  I like the drafting table as a form factor.  Here are a couple of my previous posts related to this topic:
Emerging Interactive Technologies, Emerging Interactions, and Emerging Integrated Form Factors (2008)
DigiBoard Multi-Touch Mixed Reality Game; Ideas for future design of a flexible, adjustable multi-touch surface (June 2008)