The games industry could lose any one of the big three and it will still survive. Or to put it simply any one of the three are expendible.
Nintendo - Expendable, proven in the PS1/PS2 generation. Had they not existed then? It wouldn't have mattered.
Sony - Expendible, this generation and the ones before the N64 are proof of this.
Microsoft - Again, expendible.
The point is, the three players in the market have to constantly justify their existance to you the consumer. If they don't they will drop out, its as simple as that.
This is an industry where one or two players can expand and cover the whole market, much like the semiconductor industry. So the one who would drop out of the market would hurt it the least because at that time it would probably be the least relevant and influential in the market anyway. If you want proof, look at the exit of Sega! It hardly caused any ripples at all when they left.
Tease.
