I did a talk on Matrix in one of the tutorial rooms, and it was great to see people with lots of questions and comments in the session. If you missed the talk - or have further questions: the FAQ might have the answer, or maybe the Spec itself - and there's always #matrix:matrix.org where you can find me and the whole matrix team.
At the end of day-panel on the first day, the question "are there any projects that are ready for mass adoption" was posed, and Ira picked Matrix as her answer, which was great to hear. We have come a long way in the last year, and I think Matrix now has "enough" features to be a realistic option for your IM/VoIP and group chat needs.
I really enjoyed redecentralize and hope it will be repeated! Thanks to the redecentralize.org gang for arranging it!