Since there wasn’t time to answer all questions during the Q&A section, here’s mine:
Thanks for the questions!
Subs… Well, subs have been, and continue to be, discussed internally in several different contexts as they can relate to Extensions. I am certain that something will occur in this space, and it is more of a matter of when, rather than if. Given that there have conversations around different uses subs, it is difficult to say which path is likely to be taken first (second, or third) just yet.
Variable revenue shares have been discussed internally, for both In-Extension Purchases, and Bits-in-Extensions. I expect that this will evolve as we try to find a sweet spot that balances between requirements of developers and broadcasters. It is very clear that a one-size-fits-all approach will not work for everyone. That being said, we need to start somewhere.
Monetising streamers… This already happens today! A number of developers already do contract Extension development work for streamers. Over time, we will likely provide more (and different) supported avenues for monetising Extensions; a number of different strategies have been identified, but most of these have yet to be explored.
European events. I’m an engineer, so I can honestly say that I have no idea. @Amorelandra can hopefully answer this question far better than me.
Thanks for the reply! To clarify my 2nd question: I was talking about variable pricing of In Extension Purchases, instead of the current fixed price. Like for instance last night during the Roadmap an example of the use of Bits in a video extension was paying to graffiti the video overlay, I’d like to have that price in Bits (or $ amount) able to be based on the amount of viewers (the more viewers, the higher the amount of bits). The rev share that was talked about yesterday sounds good though, I was especially excited to see that developers get a % of Bits spent in their extension!
With regards to monetising streamers: from what I understand right now only viewers can make In Extension Purchases. The extension I’m currently developing could benefit from the freemium model, offering basic features for free, with extra paid features available. If I wanted to do that right now I’d have to send streamers offsite for payment and I imagine Twitch wouldn’t want to lose out of such a large potential revenue stream.
Really looking forward to Twitch implementing multiple video extensions, since the current limitation is a big impediment for extensions like mine. Again, thanks for the quick reply 
Ahh variable pricing… that has come up in several discussions, but my gut tells me that it is further away. The trickiness there is to provide a guarantee around price through the life cycle of a transaction. It is possible to shoe-horn something in, leveraging fixed pre-defined amounts; and then conditionally determining which to leverage based upon the environment concerns.
To answer the question about monetising streams, I am going to tag in @jchow, who should be able to give you a more authoritative answer than I can. 
I’ll take “this thread” for “things that go bump (in the middle of the night)” Alex.