Midichlorians
OK, my opinion on them: They're a mistake, a device useful only momentarily to shock the Jedi as they found out how strong Anakin is. Otherwise, they detract from the sense of power of the Jedi, instead of having a direct connection to the Force, they need a conduit, a 'translator' if you will, in order to understand the Force. I think they will leave them unmentioned for the remaining films, as they are no longer useful from a plot point of view.