One of the major benifits in CX 2008 is leverage the SDK and build custom components using Adobe Flex. This will enable users to create and use their own custom components in CX 2008. For example, many users wanted a Tree Component which is not an Out of Box component in CX 2008. However using CX SDK and Adobe Flex, one can create the Tree component. Below link has some examples:
Click here for some free components
Click here if you have some dough to spend
What is your compenent wishlist? Please leave a comment. This list will give the Component Developers an idea on what to focus and develop in future.