I've been trying to make a reservation off and on myself, as well. You just never know.
There was a glitch in the system that caused my reservation to fail, so maybe there will be another glitch that can make it go through. Besides, they may open it back up briefly if they are expecting more stock.
I think with the sheer number of pre-orders, they eventually cut it off and started playing it safe. After a while, they may open things back up again, and maybe even bump up people's shipping dates a bit.
I'm going to stay optimistic and try to make a reservation a few times a day until launch day.