I never heard anything else about London, but if I didn't mention it previously, Brandenburg claimed that they will be present at the Toronto BitcoinExpo, and said meetings could be arranged there.

I actually scheduled a telephone appointment with Brandenburg but this was not kept, he claimed due to time constraints. This was the week they had that downtime a couple weeks ago (IIRC, the day just after), so I let it pass.  Disappointing though.