All the people answering gamelover about first party and motion controls are linking numbers that compare past sales. But those sales happened on very different markets for the Wii and the PS3, and as such they don't prove what could happen when
- the extended market becomes a field of contention between all competitors. Up to this point Nintendo has been almost alone in tapping it, save for a handful of titles
- motion controls are tentatively proposed to the traditional core market as an advanced form of control
None of these two seem to have happened in a significant amount, up to this point. So past sales data are a very poor indicator of how these will unfold, and how Sony will be able to push them as a first party developer.