Bieber has 127 millions shares of OPMG with a 3 year agreement. Trust me he was probably paid for by the vietnam company and they paid his airfare and hotel room in Vegas. This is probably very smart for phoneguard so they didn't have to pay for anything. Trust me Bieber is stopping by the booth with his videos and full size banners. GO OPMG
You have indeed, good to see old names return. He hasn't been vocal indeed (a bit weird for a singer :) ), but he may well just make up for it very soon.
He did shoot the videos, so we will see something of him, live or otherwise.