Many of us don't know what Bungie might surprise us with on Christmas Day but many hope for something cool.

I hope for a Santa version of the Cryptarch. Dress him up with a Santa hat and beard and a big bag with engrams sitting right beside him.
Also if his dialogues were to change depending on item upon uncrypting.
For example: Let's say you decrypt a Legendary engram, from that engram you get a rare or uncommon item. He would say "You've been naughty Guardian." And if you get something good, he would say something like, " Merry Christmas guardian."

That's just my idea of How Bungie could surprise us. Tell me your ideas in the comments, maybe Bungie will hear our request...