We rapped the couloir on September 25th, 2005 and here's what we found (directions described based on looking DOWN the couloir):
Rappel 1: There is a broad flat-faced boulder/rock to the right with a ledge system on it. If you stand on the ledge you can reach rapp slings for the second rappel.
Rappel 2: Angle left toward the opposite side of the couloir. Here there are some more rapp slings and some sloping loose ledges holding snow. As an alternative, there is an old cam left in a crack beneath these ledges where a nicer snow platform can be ade.
Rappel 3: Stay to the left side of the couloir, and another set of rapp slings can be found alongside the moat - we had to chop steps here to fit everyone (5 people!)
Rappel 4: Keep to the left and you will come across one more rapp anchor. It is hard to see until you are below it. There was a large bridged moat between us and the wall with anchors. The anchor is composed of one nut in a vertical crack, one chock-pebble girth-hitched in the same crack, and our added sling across a large detached flake beneath the crack. This rappel conveniently gets you to the bergschrund.
We needed the full 200ft rope length to reach these anchors. If you're climbing with one 60m rope, it will not reach unless you are using a retrieval line!