I think I can distil two distinct events from the running of the ESCADIZ so far.
Did China mishandle the first day?
No I don't think it did. They made the announcement and gave the neighbours time to respond. Can you imagine the press if China had sent whole Airwings of the PLAAF on day one? I think China gave others the chance to respect the new air zone and ensured that its operational posture was proportional to the reaction generated.
US support for Japan?
Best described as the minimum possible, necessary response. Posters here have been so busy talking about the overhyped media response to such a small actual US operation, that I suspect many have lost sight of the fact that it was a very small US operation.
I would further say a disappointment for Japan as the big media fanfare over not very much, means that the US will say that it has made its point and done so loudly, clearly and unambiguously so not to expect any/many more "significant" gestures.
Grumblings aside, the ADIZ is now a reality and the PRC has elbowed its way into the Airspace over the East China Sea.
A true rational response. I totally believe that the US has some of the best strategists and those decades of cold war experiences should have made them very good at handling this kind of stuff. They know exactly what cards to play and to what extent sjould it be played. The B52s were a perfect example. However I think there is a gap between US national interests and Japanese national interests in the East Sea ADIZ as well as the Diaoyu dispute. The US has way more urgent and important matters both at home and overseas. Obamacare is a mess and economy is not doing very well. The ME is a mess as well and Assad is still at power after more than two years. A few rocks in the middle of nowhere is not really what US is interested. But they do need to pacify Japan and show support for their ally in the region, that is all that matters. China should make use of this gap. Give the Yankees enough face and room to manipulate things around, at the same time slowly and steadily push Japan to the negotiation table. Strengthen cooperations especially economic ties with regional countries such as the ASEAN and Korea, which we have already been doing. The ADIZ is just another step in this direction of 'cornering Japan'. Of course the goal is not to launch a war or shoot down planes, that would be unreasonable, the goal is to force them to admit there is indeed a dispute and we need to sit down and talk about it.