Going to give a talk about Espruino. What should I mention?

That's great! I don't know if it helps, but there are some talks I and others have given on a YouTube Playlist here

Things I usually include are:

• Coding for microcontrollers is normally pretty painful. It's a steep learning curve and unless you're a pro you're unlikely to have any debugger, so it's basically a black box.
  
• Running an interpreter means it can tell you what's wrong rather than crashing, and you can inspect and modify code and variables on the fly
  
• You can even do it wirelessly with the Puck & Pixl - and can do line by line debug
  
• You could use embedded Linux like a Raspberry Pi, but the difference in power consumption is huge. Raspberry Pi Idle is about 50mA, Puck.js idle is 0.003mA - so it's over 10,000 times more. It's the difference between 4 hours on a small battery or 4 years.
  
• JavaScript is great for embedded because you're used to writing event-based code so the chip can spend the majority of the time asleep.
  
• Node.js-style APIs for filesystem, network access, etc
  
• Same APIs across all devices - Original, Pico, Puck.js, Pixl.js and MDBT42. Even ESP8266 & ESP32
  
• The Espruino boards have it pre-installed and are plug and play, but it's Open Source and is available for devices like ESP8266 that only cost a few dollars (you just have to install it on them, which can be a bit difficult sometimes).
  
  

If you wanted to give a demo, I can explain how to set up the Web IDE with a webcam as well?

Hope that's some help!