Current tomes gives i100/110 and i120/130, so next expansion I bet we will have something like i120/130 and i140/150, with whatsoever new currency it will be.

The logic consequence is have the 51+ light party duties dropping gear from i90/100 and stopping to i110, full party 'casual' raids go up to i140, and latest endgame raid giving out i155 or i160.