The biggest one is dynamic interface creation via OSC. I’ve had many people write me and express interest in this. Although it was technically possibly in 1.2 it required a -lot- of js programming and a lot of poking into the inner workings of Control. Now it can all be done via OSC messages. You can create a blank interface, add widgets to it, change parameters of those widgets and begin outputting OSC messages without ever creating a .js file and uploading it to your phone. Here’s a brief video demo:
You can try this Max patch to get an idea of the messages Control accepts… I’ll try to post documentation ASAP.