I think both camps can be made reasonably happy fairly easily.
While I love good, old-fashioned D&D traditions, I come down ever-so-slightly on the side of preferring historical armors.
I propose the following changes to the fluff of the present armor table:
Armor: Price: AC:
Boiled/Studded Leather 10sp 11+Dex
Brigandine 500sp 12+Dex
Mithril Mailshirt 5,000sp 13+Dex
Mailshirt 25sp 13+Dex(max 2)
Breastplate 500sp 14+Dex(max 2)
Dragonscale 5,000sp 15+Dex(max 2)
Ringmail 30sp 14
(chain)Mail 75sp 16
Splint/Banded/Scale 500sp 17
Plate 5,000sp 18
None of the mechanics are changed. However, I got rid of that displacer beast hide silliness, and brought back a couple of armor types that are both historical and have a history with older editions of the game: the brigandine, (non-mithril) mailshirt, and the breastplate. Roll studded leather into "regular" (boiled) leather armour (hey, they're both techniques that supposedly augment the protective qualities of leather, right?), and--in a nod to 4th edition--combine scale with splint/banded (both of which I interpret as referring to different types of 14th century-style Wisby coats of plates).
As for the pricing, I can accept that the construction of a brigandine is a sufficiently intricate operation to warrant a pricetag in line with some heavy armor types without resorting to explaining the high price with magic or rarity, as was the case with displacer beast hide.
The heavy scale armor, I imagine as a long coat of fairly large scales worn with a helmet. The brigandine I envision as one of those later 16th century styles, with hundreds of tiny plates and rivets, perhaps with a fancy velvet cover and gilt rivet-heads to help justify that price. The mailshirt needs no explanation, but I think it can be safely included in medium armor while its rich mithril cousin can be counted as light. The breastplate can be pictured either as classical "spartan" hoplite armour or as pop-culture "conquistador" style armor; in either case, it's a cuirass (and maybe a skirt), a helmet, and greaves, which image is a staple of fantasy fiction.
I confess that I have no explanation for why (chain)mail, whose construction is also fairly intricate, should be so cheap in this iteration of the D&D universe--maybe wire-drawing technology somehow evolved in advance of sheet-metal manufacturing techniques.
Anyway, I'd rather see an armor selection like the above instead of what was released. Yeah, I know that renaming items just amounts to a flavor change, but it would be nice to see an official sanction of this.