Top new features of Adobe Dreamweaver CS3
(Taken from Adobe.com)

Spry framework for Ajax- This is for Ajax programmers- For very Advanced only

Spry effects- Cool effects for objects but not a necessary component to Web Design.

Advanced Photoshop CS3 integration- Better copy and paste directly from Photoshop. Nice feature but not necessary for optimized web images

Adobe CSS Advisor- A forum for known CSS issues.

Predefined CSS Layouts- Nice for non-designers. We learn to understand CSS from the ground up.

Adobe Device Central- allows you to use predefined templates for mobile devices, like cell phone browsers.

Adobe Bridge CS3- The File Management Window is a much more logical file management tool.

Click Here for the Top New Features in other Adobe CS3 Programs