Well, for one it uses the annotation-config system in Spring 3.0 in order to facilitate easier config through inheritance and overrides, and uses AOP compile-time weaving for Spring configuration of non-container managed beans, which in RCP tend to pop up easily (like programmatically created commands).
Normally views, binders and such shouldn't take too much effort in porting, but like I said, some things are gone, like the Application singleton, the ApplicationServices locator (now services are just injected using @Autowired or are already available as injected objects on superclasses), RCPSupport is gone (again, you can use injected services now).
The simple sample was quite easy to port, most of the issues were due to the use of the RCPSupport class. Most of the effort goes into setting up the @Configuration classes.
And then there's off course the package name change. I couldn't just use the org.springframework package for something not related to SpringSource .
I suggest you take a look at the simple sample, it nicely shows the new way of configuring and RCP.
MSN: PM me please
Spring Rich Client Project Lead