I think the most interesting thing is how the x86 cpu and GCN based gpu will translate to PC in ports. It should be a much closer thing this time around.
Honestly, I don't think x86 and a GCN-based GPU will mean much at all in regard to porting to the PC. I'm certainly no expert when it comes to game development, but after thinking about it for a moment, the instruction set architecture (ISA) doesn't mean
that much when it comes to console vs. PC. In my opinion, the two largest roadblocks that PC gamers have had in regard to console-to-PC conversions would be console hardware limitations and the human factor (i.e. lazy developers and/or penny-pinching publishers).
Hardware limitations are probably the ones that we notice the most. You run into a game that has awful, low-resolution textures, and chances are that's because they're the same textures that are on the console. Why isn't the console using better textures? They don't have enough memory, and even if they did, the GPUs couldn't handle them fast enough. The PS4 appears to have a decent GPU with decent bandwidth that ought to not be too terribly limiting even considering a few years into the future. If VGLeaks is accurate, then I would be a bit worried about what the XBOX 4's limited memory bandwidth will mean for gaming. nVidia's GPU conference is going on as I write this (you can see the
Live Blog on Anandtech), and they're mentioning GPUs with on-die memory (similar to the 360's eDRAM) for 2015 that will offer close to 1TB/s bandwidth. So, it will be interesting to see how well the consoles stack up to the evolving PC hardware market.
The human factor always seems to upset us the most, and especially so when it comes from a well-known developer. A good, recent example is how Aliens: Colonial Marines came out with muddy, low-resolution textures, and Gearbox released a
4GB patch that brought high-resolution textures to the game (along with other fixes). Unfortunately, this seems to be a lot more common than we would like to see as most developers consider the PC to be an after-thought. It seems that Square-Enix is the only publisher that reliably releases a proper PC port for their games, which sounds odd given their predominance as a console developer.
Now, the reason why I don't think that the hardware ISAs will matter as much is that it still matters how you
use them. For example, PC developers mostly use DirectX for Windows, and that will be significantly different than the code developed for the PS4. As for the CPU, the difference is yet again in whether or not there are any special libraries involved. I'm not sure what Cell required, but I don't see much of a difference between using the Jaguar cores in the PS4 and the Sandy Bridge cores in my desktop... as long as it's coded in straight C++ (or any other language). No funny business allowed!
A friend of mine used to work for EPIC Games, and awhile back, he told me how much he hated coding for the PS3. Now, I'm a bit curious to ask what he thinks about the PS4, and whether it will be a better experience.