Sony is still very relevant, just not dominant anymore. And honestly I don't think they will dominate again.
The reason the PSOne/PS2 were so dominant is because they had almost all the major third party games exclusive.
You put Final Fantasy 7, Resident Evil, and Metal Gear Solid on N64 and Saturn (for the sake of this arguement, lets assume Nintendo opted to go with a CD-ROM drive instead of the failed 64DD as a way to appease third parties) and the PSOne wouldn't have dominated nearly as much, in fact in this scenario, I think Nintendo probably wins that console cycle.
Every system that Sony has released where they haven't had the top third party content exclusive -- PSP, PS3 ... they have come nowhere close to finishing first. I don't see that changing any time soon either.
PSOne - PS2 era were a perfect storm in a lot of ways. They took advantage of Nintendo being dumb enough to alienate the entire third party community and Sega's floundering business.
Sony can't "win" first unless they have a ridiculously lop sided advantage in third party support like the PS1/2 had. They're a pitbull without teeth in that case.
