I've been doing some reading on the PS4 design (based on rumors, etc), but it would appear that Sony (and MS, since the XBox720 according to rumours will have a very similar design hardware wise to the PS4), is that the PS4 core design is based around the GPU with the CPU cores grafted on it and not the traditional APU design (CPU with embedded GPU core exposed by an embedded PCIe controller between the two). Also, according to rumour the PS4 will use GDDR5 on a 512bit bus as the main RAM shared with the GPU... (something like 176GBs bandwidth between CPU and RAM vs 50GB on quad channel DDR3 setups commonly seen).
I've read a lot about the slow clocked CPU, and since most games are GPU limited and not CPU limited these days, having 8 slower cores may be better for power/heat management than 3-4 faster cores clocked at 4+ GHz. (Have you actually watched your CPU usage during game play)?
Also, I would highly suspect a UEFI based BIOS, with secure boot enabled locked to Sony keys as well to stop other OSes from being booted. (Using an existing UEFI BIOS will reduce production time/money as well as starting from a known working base for the underlying BIOS meaning less upgrades for the core system will be required). The interesting part in all of this is, how will the GPU be exposed to the game software, will the game have a basic OpenGL library to utilise or will the game have to interact with the GPU directly?
Also since the change from PPC to x86 for both Sony and MS, will mean that backwards compatibility will most likely be off the table in both instances... What will be interesting is the online store offerings by both parties and the indications of significant changes to the used game market (rumour has it MS will lock a game license to the actual console or your Live account, so you can't transfer games between consoles effectively killing the second hand game market).
Something else to consider.... nVidia only has an ARM license (no x86 license), so anything paired with an nVidia GPU will be limited to a more traditional PC-like setup (irrespective of the CPU cores being used) or they'll have to use an ARM derived CPU (ARM is great for low power, but at the higher end - not so good), or Intel, which doesn't have the GPU performance to compete with AMD or nVidia... So for a high performance CPU + GPU combination, it would appear at face value that AMD is the only company that has something to offer that will still be competitive in 3 years time... (and also have the performance to easily power 1080 HD gaming, with possible options to handle 4K screens)...
The only other options are SPARC (effectively only used in HPC these days) or PPC (relegated to more embedded stuff which is being taken over by ARM or HPC/Mainframe). Common MIPS implementations don't have the performance to compare to x86 based cores (but are competitive with ARM performance), and most of the other CPU designs are either dying or relegated to embedded setups where power requirements or core simplicity outweigh raw CPU performance.
PS. I can't be held responsible if any of the above information is incorrect... it is based on rumours, suspicions and outright lies...