PDT 2.0 was designed based on principles different to those of Eclipse PDT 1.0. For example, different techniques were used to model workspace projects. PDT 2.0 now uses an indexing and caching mechanism for improved performance and experience with code assist and navigation. Moreover, since PHP provides enhanced Object-Oriented features like inheritance and polymorphism, PDT 2.0 provides enhanced features such as type hierarchy, override indicators and type navigation for programmers who utilize these language properties.
The extension is now lighter and faster, making better use of the Eclipse framework for caching/indexing language elements. The release also includes a method for configuring your buildpath, a "mark occurrences" feature, an icon that notes overrides, improved code assist and much more.
You can grab this latest download from a Eclipse PDT page off of the Eclipse site.