I think it would be funny if you could play as Super Mutants.

IIRC It was orginally planned for FO1... But had to be removed due to timing constrains

Playing as a mutant would not provide much role-playing opportunities anyway. Vault pure strain citizens would be dipped to create more mutant soldiers. The mutants would take every town one by one, enslave its people and prevent them from reproducing i believe.

There was the option of leading a mutant revolt against the Master, if that's what your thinking about?

That would be awesome... is there any Fallout Restoration Project just like the second one?

I think I remember Ausir mentioning it a few times (just that it was intended that you could play post-dip)...

I think there was a project underway... But given some of the other cut ideas (Steam Wagons) and the lack of an official mod tool for FO1, I'm not sure if its gotten too far. The (FO1/2/Tactics) Mod community over at No Mutants Allowed is a lot bigger than here though, it might be worth asking on their boards.