in general, a leading console sells for 1 / 4 and 1 / 3 of his final LTD after the arrival of the new generation.
assuming that the Wii 2 comes late 2012, by then the Wii will be about 100 million, so end his life in the neighborhood of 125-150 million
360 and PS3 will be near 55-60 million by th end of 2012. Even if they give a bonus of 1 / 2, this will only in the 110-120 million max
and this without taking into account the hypothetical release of the Wii 2, that as a new piece of technology, would probably drain the sales competition (since it will be the technological marvel of the moment)
one inside the other, it is highly unlikely that the PS3 could become the leader of this generation
(sorry if my english is poor, google translation French -> English)