Florida's House of Representatives had a pilot project last year where they were able to leverage the OpenXML formats to make it much easier to craft a bill: http://www.microsoft.com/casestudies/casestudy.aspx?casestudyid=200428
Basically, as a bill goes through the legislative process, amendments are added. So every day, someone needs to go through those amendments that were adopted the previous day and re-generate the bill with those new amendments. They've customized Word 2007 and with the OpenXML formats make it super easy for the people generating the new draft of the bill to bring all the amendments in.
They leverage the OpenXML formats and SQL server as a way of storing the various amendments. They then built some custom UI into Word 2007 to expose the amendments to the guys regenerating the bill so that they could easily insert them. Here's a screenshot of the UI:
By automating the system in this way, they significantly improved both the efficiency as well as the accuracy with which the new drafts could be generated. While a system like this in the past would have been pretty complex, they were able to build this one with just two developers.
This system is a great example of the new types of document assembly scenarios we're starting to see pop up because of the new file formats. You can use the formats to create chunks of content to be easily inserted in other documents. As I've said before, enabling scenarios like this was one of the biggest motivators we had in the decision for moving to new default formats. We had a long history with XML formats in Office, and we saw a lot of folks building solutions with those formats. Making the XML formats first class citizens though and moving them to be the default will really help this ecosystem to grow.