I was thinking along the same lines as you. Whilst MS want marketshare, Sony are setting up for the next gen. I was reading an article on N4g which says the next Cell chip will have 4 Cell processors with all 8 SPE's working and this time the RAM for GPU and CPU may be similar to that of the 360 where it can be distributed to whatever requires more RAm at the time. (I'll try find the article and post it for you).
Here is the Link: http://www.techradar.com/news/gaming/consoles/playstation-4-everything-you-need-to-know-464657
They have the foundation over a chip to which its successors will be more powerful then the Larrabee (cant be asked spelling it), meaning, next gen they won't need to spend half the money on the Cell, they will already have BR, so again money will be saved.
The PS3 is only laying the foundation to what is to come next gen. Even Home is an indication to future planning as well as the whole concept of one in all console and entertainment centre. If the quality of the PS3 is anything to go by, the PS4 will be awesome and I don't think Ninty next gen or MS will be half as successful as they were this gen.
Saying this, if Sony wants to compete, they will need to release their next gen PS before or around the same time as MS and Ninty. No more delays!







