to throw in my tuppence worth I think the loses to both sides would have been significant, according to sites i've looked at the japanese had in thier attacking group :
6 Carriers, 2 Battleships, 2 Heavy Cruisers, 2 Light Cruisers, 9 Destroyers, 3 Submarines with the fleet, 7 Tankers, 25 Subs out ahead, 5 midget subs.
The USN had within 400 miles of pearl :
2 Aircraft Carriers,7 Battleships, 9 Heavy Cruisers, 6 Light Cruisers, 42 Destroyers, 12 Submarines, 51 Aux vessels, mine sweepers, tankers, hospital ships etc plus over 300 aircraft based on O'ahu itself.
The attacking japanese fleet if they did not know that they had been discovered would have been obliterated,
Firstly apart from superior subs and carriers they were heavily outnumbered by the US in every other catergory, secondly the japanese fleet would only have had the third wave as protection and has already been mentioned these did not consist of torpedo planes.
As the first and second wave reached Pearl they would not only of had to have tended with the fact that the majority of ships were absent but also that the americans were prepared to defend the island and a vicious aerial battle would surely have ensued, the majority of the jap planes being destroyed
Those that did survive would return back to the fleet to disover that they had no where to land and that they had to contend with aircraft from the lexington and enterprise.
The only plus for the Japanese is thier submarine force which would probably inflict a massive price on the united states navy.
either way both sides would be significantly weakened for a considerable time as they rebuilt thier forces for round 2.
please feel free to correct me on the many points i'm sure that i've got wrong.......