Lucky me! I had the great opportunity to meet several of the Open XML developers at the Open XML workshop in Redmond last week.
The workshop was quite interesting in terms of content and delivery. Tons of advanced samples related with WordProcessingML, SpreadsheetML, PresentationML, and more. The code for the labs was awesome and of course the best part was having to opportunity to watch Doug + Wouter, Brian, Tristan, and Sanjay showing lots of practical demos. After the workshop, Doug recorded some Channel 9 interviews with some of them. You will be able to watch a Linux/Java interoperability with Open XML (Sonata Software) demo, an Open-source Open XML API for Java (Julien Chable) demo, and the Package Explorer for Open XML (Wouter Van Vugt) demo. Pretty neat stuff you can do with the Office Open XML Formats.
While all this happened, I had my own Office Open XML Formats + MSDN stuff going on.
I think it's great that we finally have two samples available. Curious minds want to learn how to manipulate PPT slide decks using the System.IO.Packaging library, XML, and the PowerPoint Open XML Format. These samples come quite handy when you are considering server-side PPT manipulation.