I saw in the 5.4 patch notes that
"All permanent item enhancements provided by Enchanting, Engineering, Leatherworking, Tailoring, and various vendors and quests are now able to be applied to items of any level. This means all enchantments can now be applied to heirloom items."
That mean If I'm enhating Superior Intellect for Cloak , It will be scaled down from 180 intellect?
Yes. I am not sure of the scaling, but I would assume something similar to the way an heirloom scales; relatively linear within an expansion and big jumps at expansion breakpoints.
I would love to see a list of enchants and what they scale to at each level. I guess someone will have one eventually. Like enchant weapon windsong for a level 10 http://www.wowhead.com/item=74723