It's a mind body state that is available to those who want to do what needs to be done to gain it.
Well put, Mark. If people can get enough basic kokyu, suit (ki) and hara (these develop over time) and then put that central idea of "make unit connection; move center", Aikido can move ahead by leaps and bounds. The tricky question is getting the basic information about ki, kokyu, and hara into peoples' movements because those skills are antithetical to normal movement. As the old Chinese saying goes: "These things are not intuitive, but must be learned".
Ikeda is making a good effort at teaching in that direction.