I think that if Sony closed shop every time some other company start to talk of releasing a console more powerful than theirs about a year after their product hit the market... they would not have released the PS2 yet.. I mean, the OG xbox and gamecube released about 18 months after the PS2 (thus were more advanced) but price and content played big roles, along with timing, etc.
People are just speculating with too little in their hands, we have yet to see how long before Sony's machine will be there and how much of an impact it has, what the price difference is and how they both perform in the real world (beyond the 4K console PR speak, how does it materialize?).
Specs are an important factor for a console (the PS1 was the best performing console upon release, the NES was the best performing console upon release, the PS2 was arguably more powerful than any other console upon release, same for the 360)... people did not compare them to upcoming tech, they bought what was there, then when other more powerful machines came to be the others just had too much momentum built for them, the library made the rest... heck, even the Atari 2600 was much weaker than its competition, but they all came out later! and sold much less...
so the right question now is: is the first mover a better advantage than specs? the answer is "it depends on the execution" as MS has seen with the 360, it does not always work, even if your product is great (however, the 360 was seriously flawed).