Looks like the translucent keychains are finally popping up. MoonliteX found this while digging around Citiwalk at Universal Studios. Unfortunately, this was literally the only one they had, and the rainbow dash version was nowhere to be found.
The store she located it at was called "The Crows Nest". I really hope that doesn't mean we will have to dig through smaller retailers for one of these! Out of all of the official FiM toys, this set is on the top of my list.
Apparently they are distributed by "Big Time Toys", if that helps anyone in the hunt.
I will distribute these for you Hasbro! Promise! They are amazing! Let us give you our money.