These Are Things That I Know
What you learn in class is always different than what's being taught. Everybody brings to the table a different background, so some of what's being taught may not necessarily be new learning for every student.
With that in mind, 3 things that I learned in MMO Class:
1. Data mining isn't just a neat idea with MMO's, it's a vital measure. Data mining your players is what lets you know how healthy your MMO world is. It's also not enough to just collect the data - because you will get reams of it - you have to be able to analyze it usefully.
2. Keep your high capacity node players happy. If they're not happy, they go away, and your MMO's network of players falls apart. It'd be like if Google disappeared from the internet.
3. The slightest change can have a big effect on an MMO world. It's good to keep this in mind when trying to influence the behaviors of players. Carrots and sticks don't need to be obvious for them to work.