To not be a dead end, it needs an architecture roadmap that's being actively developed. Cell would need IBM/STI to be developing new Cells, and if there's no market for these processors, there's no point developing the chips. Cell was developed for a larger market than just PS3. Now that's apparent that it was only PS3 that provided a market, retrospectively we can say the cost wasn't worth it. If Cell2 is only going to feature in PS4, the cost of developing it likely won't be worth it. Now it may be Sony can just double up a current 1:8 Cell and that'd suffice, without needing much development, but it wouldn't provide the ease of development of a more rounded processor (think Cell with better OOO Power core or whatever).
Actually Cell scales to multiple chips, so Sony can put how many Cell they can afford into a single die without needing much development. Creating an improved SPE version 2 on the other hand is sort of a dead end without breaking backward compatibility. Is it wise to put as many Cell into PS4 as they can afford, probably not.
Without Cell in PS4, BC will be difficult. I doubt Sony want to include another BC hardware solution into PS4. But beside Cell what other good candidates for the PS4 CPU ?
I reckon the full 8 SPE Cell at higher clock speed paired with next gen GPU or two should be enough for PS4. Devs will get result (better graphic) faster with that sort of configuration compare to multi Cell with so so GPU.
The fact that Toshiba tried Cell in high-end TVs but has dropped it in favour of custom ASICs pretty much seals Cell's demise IMO.[/QUOTE]