On today's Java Posse PodCast, there is a great interview of Bill Goggin from TopCoder. He makes some really good points about component-based development, and how the market seems to be burning a lot of time developing frameworks instead of creating individual components. I couldn't agree with Bill more! There are so many frameworks out there, most of which have a somewhat closed (or at least limited) component set. It would be *far* better for Java and the market as a whole to focus on building individual components in *one* framework.
That would be one *standard* framework, of course. There isn't a single standard component framework for Java web applications at the moment - but the closest to standard is clearly JavaServer Faces. I'd like to see folks focus on making JSF components to flesh out the component marketplace. The .NET side of the fence has a huge head-start in that they have a single unified framework that works for desktop, web, and mobile. Their marketplace is already flooded with thousands of usable components that you can download and use to get your work done quickly!
Java is sooooo behind in this space!