The cell is out the window. Insiders with great consistency have said it's not in the PS4. However these insiders aren't flat out saying it's not backwards compatible. If that's the case then there are three options.
1. Gaikai. This is pretty unrealistic but theoretically possible. Sony could stream PS3 and PSN games to the PS4. It would cost a lot more than other solutions.
2. Per game emulation. Similar to the XBOX 360 running XBOX, the PS3 running digital PS2, and the Vita running PSP games, the PS4 could run PS3 games through customized emulation per game. The problem with this is it takes time and not all content will be supported, especially at launch.
3. Full emulation. This isn't possible with the current leaked specs. However it is possible that the PS4 has an extra CPU we don't know about that's specifically designed to emulate the cell. The advantage of this is the CPU would be usable during PS4 games and would slightly increase the PS4's power. This would cost Sony a lot of R&D money.
Or of course it could have zero BC but that would be crazy in this digital age. What do you think?
