Who will Bilbo's mithril coat be made for?
Durin or one of his kids - Durin V?  
An  elf-child - Celebrian?  Arondir & Bronwyn's to-be-conceived child?   Elrond's oldest son Elladan/Elrohir[they will be combined] who is  killed tragically somehow?
Theo???
Celebrimbor makes it as a sample prototype before he ultimately decides on tanning beds?
I  think it's most likely made for a dwarf since it ends up in a horde in a  dwarven stronghold, though maybe we'll get to see just how a dragon  hauls a bunch of tiny things to a central location.  (A clawful at a  time???  Smaug compares his claws to spears, not something I associate  with gathering or holding.  Maybe dragons have something like a gizzard,  like birds do, and they consume and regurgitate a load at a time.)
Oooh,  how many dragons will we get to see?  I assume there will be some  acknowledgement of the seven dwarven rings and "gold sickness"  attracting dragons.  I hope they don't consolidate into just Smaug.
I've only just started reading about the show development, it does look like the showrunners are aware of the importance of 
Cirdan's beard!