The [rusted] and [ironbound proto-drake] rewards for the  normal and heroic Glory of the Ulduar Raider meta achievements will be removed at a future date. We currently do not have an exact date they will be taken out, but it is possible they will be removed when patch 3.2 comes out or at some point after that. When we do decide to remove these mounts we will provide about 1 month of warning so players will have time to make some final attempts.

These mounts are designed similar to the Arena Gladiator mounts as rewards for the top tier of raiders and we will remove the rewards once we have introduced enough new and more powerful equipment to make the completion of these achievements easier than originally intended. Since these rewards are designed for such high-end game play, we currently plan to continue removing any similar rewards we make available in the future.

After further discussion, we decided not to remove the [rusted] and [ironbound proto-drake] rewards for the  normal and heroic Glory of the Ulduar Raider meta achievements when patch 3.2, Call of the Crusade, launches, and currently have no plans to remove them in the foreseeable future. However, we will continue to evaluate the situation and if a decision is made to remove these rewards at any point in the future, we'll provide a one month warning so players will have time to make some final attempts.