The SDK 31 update will be coming at the end of the month, most likely. The SDK 31 update is available for testing at ai2-test.appinventor.mit.edu if you would like to help test. You will want to import any relevant projects as well as your keystore from the production server if you are going to do that.
The update coming in the next few days is to address changes in Google Chrome and related browsers that will break App Inventor companion connectivity in October and also allow us to transition to serving App Inventor over HTTPS.