These people, and everybody else, know nothing for sure.
If it comes out before 2013 then yeah, it'll probably be on 360 and PS3. But after that is questionable.
It may be old hardware but it's popular hardware that will make money.
Of course not, the Xbox and PS3 are already at the end of their lifespan. If Fallout 4 is going to be any better than New Vegas it has to be on next-gen consoles. Also, Fallout games take more than a year to make.
What do you mean better than NV? Graphic wise? That doesn't matter much, so long as it's more than one pixel per object. Story wise? That has nothing to do with it.