I'm pretty new to OSGi, but I've used Spring for a long time. I understand that Blueprint gives you most of the DI capabilities that Spring provides, but I'm wondering whether it makes sense to wire beans at a "service" layer with Blueprint and wire beans below that layer with Spring, or does it make sense to use Blueprint for everything. I believe that although Blueprint provides the DI capabilities, it won't provide the XML namespacing that Spring provides, for XML contexts, at least. Blueprint certainly wouldn't provide the Java-based configuration that Spring provides.
What have other people done when building large applications with Blueprint that might also use Spring?
