Well, the GPU side is there with the current generation of PC hardware to push good looking stuff at 1080p no problem. Since there's probably 1 or 2 more generations of Nvidia and ATI duking it out before Sony or Microsoft will finalize specs for their next systems, I think some marines are due to grow hair.
As for the shift to parallel processing, I got the feeling that it's more forced by the physical limits of cranking up clock speed. Have clock speeds even shifted in the past 4 or 5 years significantly? My Core i7 chip blows away my old Pentium D from back then, but they were both overclocked about the same to the 3.8GHz range. Just seems until they figure out quantum computing or something, they're tossing in extra cores as stopgap. For a PC that works pretty well, since they're multitasking environments, for a dedicated game console, it's not quite the same.
Yeah, that's what I was referring to. That's why we're having trouble hitting clock speeds in the 4GHz range. We've just reached the limits of physics here.
Nobody likes programming for multiple cores. I think just about any programmer would rather write for a single 12GHz core over four 3 GHz cores, for instance. God knows I would! As for the PS3 architecture, I've heard plenty of people complain about how tedious it is to work with the SPUs, and aside from Sony itself, I don't think I've heard anyone give anything but the faintest praise from a development standpoint.
You are correct. Hell, wasn't there some Sony suit who said the system was intentionally difficult to code for, so they'd only attract the best of the best in terms of developers (and thus games)?

Pure marketroid nonsense. I understand their development tools aren't that great, either. You can make parallel processing pretty painless provided proper programming tools.
As for specialized hardware... that's kind of an interesting question. You'd think at some point we'd have enough generalized computing power to not need anything too specific. In some cases that's already happened with stuff like 'Winmodems'... and I assume onboard integrated audio similarly uses CPU for tasks a full fledged soundboard of yesteryear would use specialized processing for. For physics, they did come up with that PhysX expansion card... of course Nvidia bought them out, phased out the dedicated expansion and put the PhysX stuff on their GPUs.
Well, maybe that's where we'll see physics processing in the next generation--right on the GPU. It would eliminate the need for a separate chip, which would cut costs. However, if you want to do physics calculations that aren't going to be used to assist with graphics rendering, it may not be wise to sap the GPU's clock cycles for non-graphical tasks. They're stressed enough as it is!
It seems like GPUs aren't going away anytime soon, but a lot of the other stuff is just too trivial to need specialized hardware.
No, GPUs are here to stay. That much is certain. Graphics processing is just too intensive to put back on the CPU at this point, no matter how many cores you have. Maybe, at some point in the future, we'll have systems with a crazy number of cores (16? 32?) and each core could be spontaneously specialized for a given task. Maybe add additional instruction sets for physics, or add special "physics" and "graphics" modes and the like, which change the core's operation to be optimized for a particular task, but only for the duration of a specific program (or boot cycle.) If we ever get to that point we may not need GPUs anymore, but that's a big "if."
I think 2012 or 2013 will be the next console generation. I really can't see them stretching it out to 2015 even if they want to. But that generation might make a full ten years.
Given what was spent on R&D this cycle--especially for Sony--I think 2012 is pushing it.
Maybe we'll see something in 2013, but I think it will be 2015 before we're even hearing about a new Sony console. I think it's quite possible Nintendo will come out with a new console in the next couple years, and Microsoft won't be far behind, but this generation has cost Sony so much money I'm not sure they can even afford to be thinking about a new console anytime soon.