Some sources believe Sony might be planning to back away from the console market as their PS3 console is failing to win people's hearts:
The Nikkei Financial Daily reported that Sony is planning to sell off the manufacturing lines that make the Cell processor to Toshiba. However this was denied by Sony which instead made the cryptic remark that "no deal has been decided".
Obviously the talks are still on going, but the implication is fairly clear when you consider that Sony had already decided not to invest in so much R&D on finding a replacement for the the Cell. One has to wonder what, if anything, Sony is planning to stick under the bonnet of a PS4.
Most observers would say that if you are in competition with the likes of Nintendo and Microsoft the last think you try to do is cut back on R&D, unless you are planning to pull out of the market.