Today I gave a talk at The Spring Experience 2006 about the usage of Eclipse RCP together with the Spring Framework. I discussed several variants of using Spring in the typical RCP settings and ended with the theme "Spring and OSGi everywhere", where you have the Equinox OSGi runtime and Spring deployed as a set of bundles on the client side as well as on the server side. From my point of view this is a very promising combination of these technologies. You can find the slides online in the events section. And I will make the code example I showed during the talk available shortly.
Slides from The Spring Experience 2006