We're currently experimenting with OSGI in Cocoon, here are pointers to useful information.
See Also
The oscar-dev at incubator.apache.org mailing list
Discussions on dev@cocoon
General information
Licensing
Eclipse OSGi implementation (Equinox)
OSGi & Component management
Examining the Validity of IoC - theserverside.com
OSGi and Avalon Merlin - rather old but talks about placing OSGi on top of Merlin
Eclipse moving to OSGi - discuessed by the Avalon community
blocks, auto-assembly, versioning - discussed by the Avalon community
Other opensource OSGi implementations
Embeding OSGi within a servlet
Knopflerfish in servlet - discussed at the Knopflerfish forum There was also a discussion on one of the Eclipse lists or newsgroups, either platform or Equinox, but I cannot find it