I just came back from London last Sunday, where I gave a talk on best practices for Portable Objects implementation and why POF should be serialization format of choice even in pure Java applications. Gene Gleyzer, lead Coherence architect, was also there and gave a talk on the new features in 3.5, with major topics being partitioned backing map and POF reflection. Finally, Rob Varga presented annotation-driven POF serializer generator, so it is safe to say that POF was the team of the whole event. Gotta love it :)
I had a great time meeting everyone during and after the event, and hope to see you again soon. Brian was a great host (as usual), but what most people probably don't know is that he is also a great cook (although, I still think you should've cooked lamb a bit more ;)
I also had a chance to meet Rob and Ivan from Evident Software, and Ivan was kind enough to show me a ClearStone Live demo before heading to The Ship for drinks and dinner. I was pretty impressed -- if you are looking for a Coherence monitoring solution, definitely check it out.
Alas, for those who couldn't make it to the SIG, as well as for those who were there but need a refresher, here are my slides from the event.