There currently isn't a way to do this in the SDK. Looking at the DB, this is somewhat possible, but it isn't exact. There exists a table in the DB called Q2_BrowserReg that contains the browser registration information for Desktop/Mobile. There isn't enough information stored here to say for sure that the user is currently on a new registered device. You can try to pair this with the Q2_Audit table, but that is not a table we like to query from because it is so high traffic.
Starting in a version of 4.4, there is a Q2_UserDevice table, which looks like a better solution, but again, we don't currently have a way to give access to that table.