Now where the tech of the Next Gen of Sony is out....

...and where it is not THAT MUCH more powerful and not THAT much of a jump from PS3 to PS4 than from 1 to 2 and from 2 to 3 was,

do you think it could be the FIRST time in history two generations could coexist next to each other?

I mean, for smaller developers who maybe couldn't afford to invest in next gen tech / software it would be kind of lucrative to stay at this gen instead of juming to the next when they don't lose much except for a few extra options but not much of technology advance.

What are your opinions on this?

The PS4 is much, much, much stronger than the PS3. As was the PS2 to the PS3. As was the PS1 to the PS2.

Marginal diminishing returns of graphical fidelity is a very well known concept. A sphere made up of 100,000 polygonas compared to 1,000,000 do not look significantly different.

Having said that, the PS3 is quite possibly one of the worst devices for an indie developer. Any smaller developer can simply release their game on the PS4's digital store at a lower price point (with the expectation of a lower quality game).

PC has, by far, the most powerful platform. It also has, by far, the most indie developers. There are plenty of way to reconcile powerful hardware and independant game development without awkwardly supporting two distinct hardware platforms.