The San Francisco Boot Camp was a great success, with a fantastic turnout. If I got enough names I could be tempted to do a London based event at the JBoss offices, probably in October. I would probably aim for this event to be just a 1 or 2 day event, dependant on the requests I receive. If you are interested, send me an email - mproctor at redhat d0t com.
The main idea would be to get 15 to 20 like minded people together for a day or two, where we can just discuss each others problems and we in the Drools team can help you deep dive into the Drools code.