Annotation-base programming
Driven by the popularity of Xdoclet, and now standardized by JSR-175, annotations are being touted as the best way to represent support for orthogonal concerns such as transactions and persistence. Some of the features of annotation-based programming supported in WebSphere 6 are: annotation using Xdoclet, developers can create and maintain a single artifact, developers can insert metadata into source code, and it supports WebSphere's programming model (EJBs, Servlets, JMX, Web services etc.).

As you can surmise these features improve your ability to quickly develop. Now what about deployment?

Deployment automation
One of the keys to getting development and testing done sooner is the ability to deploy applications quickly. In the past, getting applications deployed to WebSphere, on occasion, took some effort. With WebSphere 6 you can automatically deploy "on-the-fly" while still within an editor. Just some of the other deployment automation features are: support for local and remote servers, and support for fine-grained application changes.

The automated deployment features certainly improve your ability to make changes, and get them installed and running quickly.

Change triggered processing
Another important step to make deployment easier is the ability to make small changes to the deployed application without a full reinstallation. Some of these improvements are supported in WebSphere 6, such as the ability to execute operations based on certain changes in the key artifacts of the application, the ability to create new artifacts based on existing artifacts, and the enablement of a "Hot Directory" concept for quick updates and deployment. These features certainly improve "hot deployment".

Application Server Toolkit
The ASTK (Application Server Toolkit) that began with version 5 has been updated in version 6. The ASTK provides WebSphere developers and administrators with a set of Eclipse-based tools for assembling, deploying, debugging and profiling J2EE applications.

Let's briefly review some of the features. Included in the version 6 ASTK is Eclipse 3.0 workbench and JDT (Java development tooling). JDT allows users to write, compile, test, debug, and edit programs written in the Java programming language.

Also included are Deployment Descriptor editors, including the WebSphere extensions and bindings, Module/EAR creation and manipulation, debugging and Profiling/Tracing tools, and Application Server Tooling with configuration validation, and local and remote WebSphere Test Environments.

In addition, you'll find the Universal Test Client, Web services Deployment tooling, EJB Deployment tooling, and EJB CMP/RDB Mapping. All of these features, along with WebSphere's Rapid Deployment capabilities, really enhance the development and deployment capabilities of WebSphere 6.

Other notable changes
There's a lot packaged in WebSphere 6. In fact, too much to pack into one article. But you should at least be aware of some of the other features. The features you may want to consider researching deeper are administration changes, including an enhanced EAR file, the ability to introduce small changes into already installed applications, Add/Remove modules from installed applications, improved template structure, supporting more templates for different machines and environments, new binary packaging, and safe guards preventing applications like the Admin console or File transfer Applications from being deleted.