I'm not against the concept of Midichlorians. As has been mentioned earlier, it's a nice way to explain why the Force runs strong in some families. But, as has been mentioned also, they just don't do anything with it. The concept is just thrown out there, and personally, I think it just raises questions that are never answered.

For example, what happens when a Jedi loses a lot of blood? Anakin was said to have such a strong connection to the Force because of his midichlorian count, so does this mean that when a Jedi loses a lot of blood he loses (some of) his connection with the Force? What about blood transfusions? Can you make non Force sensitive person sensitive to the Force by blood transfusion? Also, if Force sensitivity is genetical, this means Sidious could have cloned himself a new apprentice, rather than go through the risky process of recruiting a new one. And instead of Fett, he could have cloned a Force user and create himself a whole army of Sith Lords.