An updated version of Proofing is in the Workspace. You'll notice things moved around a little bit and Proofing comments now appear right next to their marker.
Guest Reviews Public Release
Guest Reviews graduated out of Labs and are available on any account with Proofing and Approvals. Friendly note: you may have to turn it on for your account.
Who Something is Shared With
Mass Actions for Users
Use mass actions from the Users tab now. You can add multiple members to a group, take people out of a group, and more.