Image is everything! Marketing departments spend countless hours establishing corporate identity and defining exacting rules about logos, colors, and fonts to ensure a consistent visual experience for customers across a variety of media. Web applications are certainly no exception to rule, and complex corporate look and feel requirements have become the norm on web projects.
Traditional SharePoint web part development makes it a bit difficult to establish a clean separation between your code and the user interface, which may not be a problem for a single in-house development project when you only have to worry about a single corporate identity. However, if you are an Application Service Provider wanting to build an application and then offer it to a variety of clients, or you are a consultant trying to make a reusable code base, then it can certainly be an issue.
Rebel Developer's Templated Web Parts takes the pain out of building highly brandable, ajax-enabled web parts. Just download a copy, check out the tutorials, and start coding.