We have to realise that the ps3 hasnt yet hit mainstream market price range. Depending on future support i woukld say the ps3 has a chance. The 360 doesnt. Especially given the need to pay for online play.
With that said, none of this influences what is the outcome of the gen that is now ending. The wii sold the most and the ps3 and 360 sold similarly comparitively. The wii has run its course as a product and will be withdawn in a year or two, same with the 360, but the ps3 should last a bit longer.