I understand the need for this - Blacksmithing having one of the best stat-perks in crafting at the moment, and going to play a much bigger role with the Lightning Forge in 5.2, making players go farm old mats in CRZs with low node respawn rates to cover nilla plus three expansions of content to get into relevant stuff is quite a drag. I assume Blizzard intends to do something similar with all professions in the future to allow players to not want to pull out their hair when changing professions.
That being said, a lot of current smiths take a lot of pride in their profession, recipe collections, and the work we've had keeping smithing when it was not the best statistical profession to have. I propose something which will keep the original leveling process in tact for those who want to put in the extra effort, or skip-able for those who just don't care. Much like cooking organized recipes by their land of origin / expansion, and had a new category for the quick-leveling recipes, blacksmithing could be divided into historical and current categories, each with their own leveling requirements similar to the six ways of cooking in Pandaria. Make all Pandaria smithing recipes the 525-600 skill section, and allow the fast levelers to make use of them. Then in future expansions, the 600-675 segment will be what is leveled up, and the new recipes will be contained there.
This would mean those who make use of the quick leveling feature will get to make current gear, but will not be able to learn the discovered plans or trained plans of past content without taking the extra time and effort to do so the long, painful way that current smiths have in order to level up the independent sections of older content. It will provide us with the ability to make more useful gear for Transmog without feeling that all our hard work can be made up by anyone in 30 minutes of crafting, but still obtainable for those who want to put in a little extra effort.