PS3 would sell A LOT more, especially due to the increased momentum in the beginning. 360 would be doing considerably worse. Wii could possibly have still been leading but with a much smaller margin against ps3.
The increase in demand on ps3 would not only decrease the demand on 360 but also wii, because many casual users who dont buy a ps3 for its hefty price and just dont trust ms or xbox as a brand end up buying a wii. Also if more had bought ps3 in the first place, "wii awareness" would be much smaller, and the ps3 could have even rivalled the wii for the first place!