Here are the new features as given on their site:
Redesigned Engine – Benefit from superior program flexibility and more accurate scanning methods with all-new program architecture. Improved Code Sequence Identification (CSI) Technology – Boost your privacy protection with precise detection of embedded malware, including known and emerging threats. Incremental Definition File Updates – Save precious time and resources with smaller update files resulting in faster download times. TrackSweep - Control privacy by erasing tracks left behind while surfing the Web on Internet Explorer, Firefox, and Opera, with one easy click. Multiple Browser Support – Choose Internet Explorer, Firefox, or Opera with expanded browser support. New Straightforward User Interface – Effortlessly maneuver the complexities of malware detection and removal with our new user-friendly interface.
You should note that Ad-Aware 2007 is NOT Microsoft Vista ready. However, all valid licenses will be upgraded to the Vista compatible version for free upon release.