I have no doubt that nearly everyone is familiar with the phrase "the right tool for the job" when it applies to construction. Well, that same adage applies directly to computer software and especially RIAs.

With rich internet applications there is always a focus on the user. The ultimate goal is to make a task easy for the user, and the application is to aid in the user's productivity. This sounds to me like this is a tool...

Tool: a device or a piece of equipment that typically provides a mechanical advantage in accomplishing a task or enables the accomplishment of a task not otherwise possible

While your application may not actually be providing a physical advantage, it is providing an intellectual or creative advantage, or a means to accomplish a task.

This is an important thing to keep in mind when developing a RIA. Your application is built to serve a purpose. Whether your application is calculating budgets or financial statements, projecting business needs, enabling sales, distributing information, enabling communications, providing a visual representation of statistical information, or enabling a creative outlet, it is built to serve a purpose.

An emphasis on design must never forget about the original needs of the user, and how to make the user's tasks easier. Focusing on the 'easy' development issue should never precede the means to accomplish the original task.

This is extremely important in RIAs because RIA technologies enable a great experience. It is up to the development team to create that experience, and make it applicable, and worth using.