As others have said... this is a JOKE. There would be no market as it could not natively run any software. Linux would be the only practical OS, and it would only run software ported to that architecture.
Cell is old news, a 5870 blows the pins off of a lowly little Cell processor as will the GT300. This isn't 2006 anymore. I do think that the PS4 should use the cell - for BC and developer good will, but only a fool would try to pair a cell against an HD5800 series powered X720. There will be a separate GPU.
And for those people blinded by fanboyism that thing that this would pose any threat to Microsoft (you are soooooo clever using the dollar sign, I wi$h I had thought of that), your logic is so faulty that I don't know where to begin. In fact, I bet that M$ hopes that $ony DOES try this crazy scheme so that $ony gets stomped and lose money. M$ would be laughing all the way to the bank on that one.
One thing I have to add to this. If you are going to use M$ then you have to do it correctly with Sony as well which is -$ony