Spring AOP can advise any Spring Bean. So if you want to advice a class you have as a Spring Bean, you just define your Pointcut expression to match those classes and methods. Then when your ApplicationContext gets created Spring automatically creates Proxies for those classes. There isn't anything special you need to do with Spring MVC to add AOP that you wouldn't do with any Spring application.
Yeah, that looks nice. You are now using the Annotations and now your classes are truly pojos. Which means you can write simple unit tests for all the classes including the Aspect class. But you will have to stub/mock out a JoinPoint object. There is a way to have Spring go into the JoinPoint directly for you. Examples of that are in the Spring Documentation under the AOP section.