Chronicles says No. Amazing that this is still being discussed and people still bringing up myths that have been debunked years ago.
1) In August 1945, the Japanese were NOT on verge of surrendering. They were looking for a way to end the war but key player, The Army C-in-C, whose consent was required, would only consider a modified surrender. This would entail Japan withdrawing the troops from foreign soil, no occupation of Japan, any Japanese war criminals being tried by the Japanese. Its unclear whether they considered Korea, Formosa, or Okinawa "Foreign Soil".
2) Even after the Emperor intervened, the A-bombs, and the USSR declaration of war, the Army still attempted to kidnap the Emperor and continue the war. This attempted coup only failed because (1) quick thinking by the Emperor's aide (2) Luck (3) the Loyalty of a key low level Japanese officer (4) the unwillingness of the Army C-in-C to explicitly support it. Still it was damn close thing.
3) The planned invasion of Kyushu Island would have cost at least 30,000 American lives, not mention 400,000 Japanese soldiers and and equal number of civilians.
4) The USSBS states Japan probably would've surrendered by November 1945 even without an invasion, due to blockade and conventional air attacks. Maybe, and this may have been less costly than an invasion in AMERICAN lives, but it would've been much more costlier in Japanese and other lives. Why?
(a) there was a large land war going on between the USSR and Japan in Manchuria and Korea. In three weeks in August the Japanese had lost almost 100,000 army dead and the Soviets 10,000 - had the fighting continued through September this death toll would've at least doubled. Tens of thousands of Japanese civilians were also killed in the fighting.
(b) Large numbers of Japanese soldiers were "withering on vine" in the Philippines, New Guinea and the pacific islands. Tens of thousands would have starved to death if the war had gone on another 3 months.
(c) Large numbers of Allied POWs and Dutch internees were also starving to death.
(d) Millions of Chinese and Japanese were still fighting in China. Tens of thousand of soldiers and civilians were dying ever month from disease, starvation, and battle.
(e) Indochina, Indonesia and Malaysia were still under Japanese occupation and civilians were dying of starvation.
(f) In September 1945, the British had planned to invade Malaysia, the Australians Java, and the Soviets Hokkaido - result tens of thousands of deaths.
5) Even without an invasion, hundreds of Americans were dying at Sea and in Air battles over Japan. During the last six weeks of the war, we lost 300 men a week in B-29 air raids, Kamikaze and Submarine attacks. We were also still mopping up over 100,000 Japanese troops in the Philippines.
6) A Japanese famine was narrowly avoided in the Spring and Summer 1946, had Japan delayed its surrender till November 1945, the famine would've been much worse and hundreds of thousands would've died.
7) The USN while opposing an invasion, wanted to seize ports in China and also several small islands in the Ryukyu's and Cheju.
So, the A-Bomb hastened the surrender and ultimately saved lives.