The FBI corruption has been going on for a long time. Remember when Clinton wanted to dump the Secret Service and use the FBI for his personal protection?
The only way it can get cleaned up, IMHO, is for a President to be committed to fixing it (Bush is apparently not interested). It would do a lot of good to bring in an "outsider" to run the bureau. A police chief (one who worked his way up, not a political hack) from a small to medium sized department would be a better choice than this Mueller selection.
Taking police department reform efforts as an example, it would still be quite difficult for an outsider to fix things. There's just too much political baggage.
There needs to be additional political pressure from another source. If states, who are responsible for protecting the rights of its citizens, were to respond vigorously to each and every incident of abuse, it might provide the necessary pressure. We as state citizens, should in turn pressure state officials to do this every time, like clockwork.