This is well thought-through and interesting:
Digital Web Magazine – Web 2.0 for Designers: “In Web 1.0, there were two stages to visual Web design. In the early years, designers used tricks like animated GIFs and table hacks in clever, interesting and horrible ways. In the last few years, CSS came into fashion to help separate style from structure, with styling information defined in an external CSS file. Even so, the focus was still on visual design%u2014it was the primary way to distinguish content and garner attention.
Enter the Web 2.0 world, which is not defined as much by place and is less about visual style. XML is the currency of choice in Web 2.0, so words and semantics are more important than presentation and layout. Content moves around and is accessible by programmatic means. In a very real sense, we’re now designing more for machines than for people. This may sound like we’re in the Matrix, but in the words of Amazon.com CEO Jeff Bezos, “Web 2.0 is about making the Internet useful for computers.”
What does this mean for Web designers? It means designers have to start thinking about how to brand content as well as sites. It means designers have to get comfortable with Web services and think beyond presentation of place to APIs and syndication. In short, it means designers need to become more like programmers. Web 2.0 is a world of thin front ends and powerful back ends, to paraphrase Bezos.