In reply to MG:
yes exactly. if you go up there i will be interested to hear what you make of it. the oberaletsch glacier is fine: lots of rubble. I couldn't face climbing the ladders back up to the hut so we just pressed on down the glacier (mostly true left bank) to the bridge at the snout (point 2127). The river runs underneath the glacier there and its possible to easily cross from the the true left bank to the right bank and join the south end of the bridge easily. You can't get get to the north end of the bridge as its up some vertical slabs
if i did it again i would just go up and down from the bivi (5 star) on the other side. Pots and blankets but no gas or stove. if you do do that, crossing the aletschglacier at the marjelenseen is easier at the moment than the crossing near the roti chumma..