I agree, the Academy really does need to make an absolute ruling on where the anthology series will compete. They should all be required to compete in Miniseries or they should all be required to compete in Drama Series (or Comedy Series if applicable). Allowing them to decide for themselves is ludicrous, even if I am looking forward to the Breaking Bad vs True Detective cage match in all of the drama categories.
Luther, like Sherlock, is in the only place it can be. The Academy ruled in their favor, so they stay in Miniseries.