I happen to be someone who actually likes Spring. A few months ago, I was asked to do a proof of concept project; it was basically a event organizing system with a plug-in architecture.
A little google fu later and I found out Eclipse used OSGi for its plug in systems, Netbeans was going to support OSGi for their plugins, and Spring had an OSGi container solution called Spring DM AND Manning had this book in MEAP. I downloaded the earliest copy, ran through the "Hello World!"s and was on my way.
Then I actually had to implement OSGi. Packages wouldn't load, they would load in the wrong order, jars weren't OSGi aware, etc etc etc. After two weeks of long nights of frustration I gave up. The next morning I wrote a classloader and was up and running in about 2 hours.
To add insult to injury, SpringSource gave Spring DM to the Eclipse foundation and washed their hands of future development.
TL;DR; If you want to use OSGi + Spring DM: Don't, Spring gave DM to Eclipse and OSGi is a shitstorm waiting to rain itself out. Write your own classloader and in two hours and 200 lines of Java you will have 80% of OSGi and 99% of what you care about.