It'll be interesting to see these new consoles come out, which will be (hopefully) around the time that I build myself a new rig that will once again surpass them. If they can somehow create a device that's on par with an i7 (or high rated i5)/SSD/GTX 1080/144p device THEN I'll be impressed.
I don't think you'll see anything like that. An i5 is about $200 on it's own with an i7 being $300 and up depending on the model. Then the GTX 1080 at $600 costs more by itself than they would be able to charge for a console. An i5 and a 1080 puts them at $800 and that isn't even including RAM, storage, blu-ray drive, casing, fans, power supply, controller, etc....
I know that they can get significantly discounted hardware because of the sheer number of units they would be buying but I would be surprised if either of the new consoles are stronger than your current GTX 960 build. Considering that the original PS4 has a GPU comparable to my old Radeon 7850 getting to the 960/970 equivalent would mean that the new consoles were 2 to 3 times more powerful than the original. I doubt we will see that huge of a jump if they want games to still be compatible with both versions of the hardware.
There really is no point to the 144p thing because people would need to hook their consoles up to a monitor to be able to see it. As far as I know, there are no TVs that are capable of displaying more than 60 FPS. The ones that are labeled with higher refresh rates like 240Hz still have 60Hz inputs. They just display each frame 4 times.
As long as games still run okay on the original hardware I probably won't be buying the new models unless the ones I own die. My worry is that games will start coming out that run worse than the 900p/30FPS we are already seeing on many new games. Developers are going to start targeting the newer hardware and they totally should. The problem comes when we start seeing games that aren't also optimized well for the original hardware. As long as they scale the graphics options down properly it shouldn't be a problem but we all know that there will be games that do a bad job of this.