Here is a nice link describing the features of Spring MVC:
The information may be outdated with Spring 3.0 just around the corner.
One of things I like about the Spring Framework in general is that it's not very intrusive. Depending on your requirements, you can use the Spring Framework without: extending any class, implementing any interface; nor writing any adapter classes. This makes the framework extremely flexible because you are not locked into their application programming interface (API). If you're reading this blog, then you probably know that using open source frameworks is a way to avoid vendor lock-in. However, using open source alone is not enough to prevent vendor lock-in. We also have to think about API lock-in. The more your framework requires implementing/extending framework specific interfaces/classes, the more at-risk you are to API lock-in.
The Spring Framework also has a la carte style approach of integration into your existing software components. You use what you need and can add the incrementally framework as you evolve as a developer. In my current project, I started off using Spring's mock (stub) objects for testing (instead of writing my own MockHttpServletRequest). Then I used Spring's Object/XML Mapping (OXM) framework to domain convert objects to XML and vice versa. Now I'm looking to use Spring's MVC framework and eventually move all my object configuration and construction using Spring's core bean container.