How documents can learn from data

Multiple views Document developers are typically used to single views of information. Graphic designers, scientists, and others are used to precise control over the information they create. XML offers the opportunity to look at information in more than one view, which doesn't always make those folks happy.
Building information from data Web developers have long been used to building pages from information stored in databases. After a few years, the distinctions blur and it all looks the same. XML connectivity with database storage may blur with XML document processing.
Processing chains Data-oriented developers have long been used to piping data processing using pieces to build an overall architecture. Document developers have typically been used to a smaller chain, and focused more on the results than the chaining.
Communications as combination of documents and data The blurring of documents and data is probably the largest 'underlying message' of XML.