I was crossing the Col du Passon this morning to connect from the Grands Montets to Aiguille du Tour. I noticed lots more skiers than I expected. I talked to a couple of them and they said the "normal" route now for the Chamonix - Zermatt haute route is to go from the Refuge d'Argentiere to Cabane Trient by crossing Col du Passon and Col Superieure du Tour.
Because the north side of Col du Chardonnet has changed - ? like a section collapsed so it got much steeper ? Two American friends told when they crossed Col Chardonnet to do the Three Cols tour, they found a long fixed rope -- and even with that fixed aid, they still found it more difficult than when they descended N side of Col Chardonnet years earlier.
The new fixed rope is also mentioned in a CampToCamp.org report for the Trois Cols tour.
Someone know more about this?
P.S. Since these two passes are easier than the "old normal" Haute Route start, it seemed that one English-speaking party added a side trip to climb the normal route on the Aiguille du Tour south peak -- which they sounded pretty happy about.
In reply to kenr: I remember some years ago there was a small bergschrund on the north side of the col that was a bit awkward - the upper lip collapsed beneath me as I contemplated possible routes. This schrun could have got very much larger, there was no way round it.