Sony played their hand very close to their chest this time around. Compare that to the PS3, and how much Sony had been banging on about Cell. As far as my hazy memory goes, Cell was announced as being in the PS3 a good 18 months before the console was released.
Combine this with the shenanigans with MS and IBM, where the Xenon CPU was derived from the same R&D that produced the Cell. MS would have had a far clearer picture of what the final PS3 would be like, a long time before it hit the market.
Two areas that Sony have been unrecognisable from the pre-PS3 era. Not only have they produced a console with ease of developed at the fore (so based on common x86 tech, built using a mature fabrication process), they've also improved their legal team and made sure AMD couldn't fuck them over like IBM did 8 years ago.