To be honest I don't think three consoles is really ideal anyway. I think this would be good for both Sony and Nintendo in terms of generating more profit for everyone and good for the consumer in the end as its less hardware for everyone to have to spend money on (leaving more money to be spent on what's important).
It's good for the future of the game business as we know it too IMO iOS/Android gaming is a problem for the industry and needs to be confronted if Sony/Nintendo want "their" style of industry to continue to flourish.
2 consoles is enough to ensure healthy competition (see MS scrambling to change many of their XB1 policies due to the PS4) ... three just creates one more system that a developer has to stretch their resources to provide for. And even if all three are good systems, that really isn't a great situation for the consumer, because then to get all the good games (assuming all three have good games), you end up actually paying more for your hardware bill at the end of the generation.
The industry with the exception of the last cycle, where I think Nintendo just came upon one of those "once in every 20 years" type ideas with the Wiimote/motion gaming ... traditionally does not support more than 2 consoles strongly at a time.
Turbo Grafx 16 got the raw end of the deal versus the SNES/Genesis for example, Saturn fizzled versus the N64/Playstation, etc, and the failure of the Saturn sent Sega financially into the sewer.
