Spring is getting towards more annotation style of coding. It introduces the @Controller annotation to define controllers. If you use this annotation, you don't need to extend any of the controller classes. This annotation was there in 2.5, but the Spring team has decided to deprecate the classes in 3.0, to favor the MVC annotations.
In case anybody is interested, there is a video called "Spring Framework 3.0, The Next Generation" on the excellent InfoQ website, introducing some of the new features in Spring 3 and relating them to Spring 2.5 and Java 5/6. The video is an hour and 15 minutes long, so get yourself a cup of coffee and make yourself comfortable!