Some people have been circulating card lists based on the cards in their own collections, but Irunachan on the MLP Trading Post found Enterplay’s own official list. The PDF (found here) is also a checklist.
40 is “untitled” aka Derpy
There will be 9 promo cards: Pinkie, “to be announced,” Rainbow, “to be announced,” Fluttershy and 4 more to be announced.
The Princess Twilight puzzle set is most likely the cards in the Enterplay/Ultra PRO album.
Foil Stickers are not available through packs and will most likely be “promos” as well.