An interesting tidbit about Tisha B'Ab at Mikveh Israel that I recently stumbled upon. After the unification of Jerusalem in 1967, Mikveh Israel (at least during Rabbi Muleah's tenure) stopped the practice of covering the Hekhal with black and -- after the declaration marking the number of years since Jerusalem's destruction -- added a declaration setting forth the number of years since Jerusalem's liberation. These innovations have since been discarded, and we've reverted to the traditional service.