For my class, I realized it would be useful to my students to understand how Meteor departs from the standard request-response cycle and the implications.
Unfortunately, the screencast turns out to be 30 minutes long, which is about 20 minutes longer than I like for my screencasts. But I couldn’t talk any quicker. 
So, if you’re a Meteor newbie, or know someone who might benefit from a high level architectural overview, here’s my take: