This isn't a post on XML or the file formats, but I just saw this and wanted to link to it. Just the other day a tool was posted that allows you to do redaction on a Word document. You can get the download here: http://www.microsoft.com/downloads/details.aspx?FamilyId=028C0FD7-67C2-4B51-8E87-65CC9F30F2ED&displaylang=en

For those of you not familiar with "redaction", it's essentially taking a document that has sensitive information and black lining those sensitive pieces of data so that the document can be released. The trick is to make it so that the document itself maintains the same layout (otherwise you could just simply delete the sensitive text). I've seen a number of tools out there that try to do this by drawing black lines over the content, but anyone can still access the text underneath if they know how to read the file format. In this solution the content really is removed. Here is a little blurb describing the tool:

The Microsoft Office Word 2003 Redaction Add-in makes it easy for you to mark sections of a document for redaction. You can then redact the document so that the sections you specified are blacked out. You can either print the redacted document or use it electronically.

Sensitive government documents, confidential legal documents, insurance contracts, and other sensitive documents are often redacted before being made available to the public. With the Word 2003 Redaction Add-in, users of Microsoft Office Word 2003 now have an effective, user-friendly tool to help them redact confidential text in Word documents.

I always love these kind of tools because they show how extensible the applications are. In this case we have a group in Microsoft building solutions on top of Office. There are also a ton of great 3rd party tools that build on top of Office. The new file formats are going to make it even easier to build solutions that do really powerful and more vertically focused solutions.

-Brian