Here's what we know so far:
- Pierre can be crafted by engineersQuestion: Will my engineering character have to be level 90?
- Pierre is BoP
- Pierre CANNOT be caged and traded
- The schematic that teaches you how to craft Pierre requires 500 engineering
- This schematic is also BoP
- The schematic that teaches you how to craft Stabalized Lightning Source (mat necessary to craft Pierre) requires 500 engineering
- This schematic is also BoP, as is the crafted item
Answer: Most likely.
Question: Where do I get the recipes to craft Pierre and the Stabalized Lightning Source?
Answer: Most likely the Isle of Thunder (new daily quest hub in 5.2)
A Wowhead comment that was updated recently, mentions that both recipes required to craft Pierre drop from Notes on Lightning Stabilization. This item is the reward for completing the quest I previously mentioned in another post, Stabilized Lightning Source (starts from the item Peculiar Energy Source, which drops from the NPC Itoka on the Isle of Thunder).
So although the recipes only require 500 engineering, you'll still need a level 90 character to get to the Isle of Thunder and complete the quest.
It might be worth trying to get a summon to the isle, killing Itoka and attempting to loot the item that starts the quest. I doubt that will work though, since the quest itself is flagged as level 90. Then again, since it's still the PTR, there wouldn't be any harm trying it out? :P
Things could still change between now and the release of the next patch, so we'll just have to keep a close eye on the PTR.