For those of you looking into what type of Java support there is for the OpenXML formats, you should check out this project on SourceForge where they are building a Java based OpenXML API. http://sourceforge.net/projects/openxml4j/
Up until now, Java developers had to stay at a much lower level using XML and ZIP libraries. The formats are pretty straightforward and of course fully documented, but it's always nice to have some of the basic building blocks abstracted. System.IO.Packaging is available to .net developers which allowed for a level of abstraction from ZIP and the packaging model. It's great to see other tools like this popping up though for different languages.
Julian Chable was the founder of this project, and he was out in Redmond last week to attend some of the OpenXML workshop that we hosted. He talked on camera with Doug Mahugh for a bit about the API project, and they just posted it up on Channel 9. Take a look: http://channel9.msdn.com/ShowPost.aspx?PostID=292715