Adm. Nimitz once said that the Kamikaze's were the only thing that really came as a surprise to him. I've often wondered; had Japan accepted the Kamikaze concept earlier would it have made a difference? My feeling is, little if any.
Let's make the POD the Battle of Santa Cruz; October 25-26, 1942. In this battle the IJN's air arm suffered heavy losses from USN AA, particularly from BB South Dakota (and this is before the proximity fuze). During the battle a Val dive bomber deliberately crashed into CV Hornet. This act of sacrifice is noted and remembered.
The Naval High Command and surviving pilots discuss the situation. It is agreed, Japan cannot withstand such losses for long. The younger pilots volunteer for Kamikaze duty, knowing that their sacrifice will produce results instead of their dying without acheiving anything. The more experienced pilots also wish to join but are refused, they will attack after their comrades have weaked the US fleet.
The main differences I see are:
1) Higher initial US losses - This is due to both surprise and the difficulity of dealing with these sorts of attacks. The proximity fuze is still not available, AA Batteries still not up to 1944 standards and the "Wildcat" is not as effective as the "Hellcat".
2) The US will push forward development of the "Hellcat" as well as push work on making the "Corsair" and other aircraft carrier-qualified. It would be interesting to see if the "Mustang" or "Thunderbolt" could operate off carriers!
3) Work on the proximity fuze will continue, but I don't think work could be pushed any faster.
4) The most effective anti-kamikaze weapon, the 'big blue blanket' (large numbers of fighters), will quickly be adopted but, as I said, the "Wildcat" isn't as effective as the "Hellcat" so losses will still be high at first until newer and better fighters become available.
There might be a small butterfly effect if aircraft slated for Europe end up in the Pacific, likewise if the carriers are forced to operate more fighters and fewer attack planes this may very well slow up the offensive slightly.
But in the end Japan will still lose, I see this only buying them a little extra time.
Any thoughts?