Admittedly, these problem domains have seen an influx of new tools and a variety of IDEs to simplify the solution development process (bringing the more complex problems into reach). In large part, however, most of these are still operating under a waterfall lifecycle and I suspect only a few have gone the way of XP style practices.

Here I’m jumping paradigms: tool over problem domain. Scripting languages have made leaps in the last 5 years - Python, Perl, JavaScript, introduction of Groovy, Rails, and Ruby. These languages have seen a broader array of problem domains than traditionally exposed to. Groovy and Ruby have changed the implementation tactics of delivering dynamic content over the web. As a consequence, AJAX (Web 2.0) has arrived on the scene.

For the heavy lifters, today being Java and .NET, the web environment has seen a spike in the development of frameworks, most of which are open source. Frameworks have introduced gravitational changes in the web development industry - fostering an integration development process over unit by unit development process. Here XP and Agile methodologies fit best, and the new (or re-labeled) methods of tomorrow are evolving with this industry.

It is the web development arena that we see the most rapid evolution. Internet-borne solutions are the target today for much of the innovation. Just now, we’re beginning to see the other industries ramp up their pace: bio-engineering, real-time/embedded systems, aeronautical engineering, etc. It appears that commerce has been leading this pack - the drive to bring marketable services to the user at home.

So I think it depends on the industry your in. But I know (and agree) that if you lag the web sphere for long - you better be able to sprint if you ever want to get back in the game. There’s one other point worth mentioning: even in the web sphere, there’s degrees of hotness, any of which will enable you to move forward on the leading edge of the wave.

But in reality, very few companies can afford to adopt each technology as it comes out. What really happens is that most organizations adopt a technology and stick with it for 7 to 10 years, then re-evaluate. During those years, there’s not a lot of revolutionary new skills coming in, just refinement and minor updates to the old ones. Then after about 10 years, the organization plays catch-up to current standards — perhaps– and the cycle repeats. Only when the company changes its technology is the learning curve really encountered.

None of this is to discount your main point, which is to evolve or become extinct. I have seen dozens and dozens of people who don’t keep their edge, and when the time comes that technology does change on them, they have forgotten how to learn new skills. The ability to learn new skills is a skill in and of itself, that ability must be practiced continually or you forget how to do it when your livelihood depends on it.