Great cloud, a wonderful blue color, dramatic mountains with snow. I think you could crop out more of the lower clouds along the bottom to emphasize the mountains even more.
If anything I'd go the other way so that the mountain range splits the shot onto two equal halves...
Having seen more Mont Blanc shots than I care to remember, I didn't expect to be blown away by this post, but I really was. It gives a completely new perspective on it. Good work.
p.s. I'm trying to figure out where you shot this from... I've stayed in Les Houche before, but it can't have been that far around on the other side of the valley, as you wouldn't have seen the MB peak...