I just did my ApacheCon talk about OSGi best practices.It was the last slot but the room was still almost full. In general the OSGi track had a lot of listeners and there were a lot of talks that involved Apache Karaf. So I think that is a nice sign for greater adoption of OSGi and Karaf.
You can find the Slides at google docs.
The demo application can be found inside my Karaf tutorial code at github.