Just yesterday I've seen a bunch of canceled buy orders transformed into market orders. If this trend continues we will see drying up support pretty soon, right now people can still compensate by canceling sell orders so the overall order list looks the same.
Either way that are definitely the first signs of exhaustion.
I disagree with your conclusion. While buy orders may become market orders the graphs show no dramatic drop outside of the immediate buy events and have increased in general AND remain extraordinarily high. Today had the highest buy order depth EVER and even right now is equal to the high of yesterday.