No one truly knows what to expect. You can either whine and bitch about the "party being over" or you can do what all successful traders do and adapt to the conditions. Yes, things will be different but different can also be good if you learn to play the game a new way. As far as I'm concerned the NYSE has changed a ton in the last year anyways before the full rollout of the hybrid system. I rarely depend on the "price improvement" prints because I hardly see them anymore anyways. But, I've found new ways to make $$$ from what I've seen and I'm sure the same will be true come Oct 6th. It may take a few weeks to get accustomed but what can you do?