With a recent surge in "Why Can't I Mail BoA Items Across Servers?" threads, I've decided to toss this idea out into General Discussion. It originally appeared in another thread (http://us.battle.net/wow/en/forum/topic/1921698507?page=1#18) as a response post, but I've since expanded on my thoughts and feel that, as its own thread, there's a better chance it will be seen by the folks who can implement the idea.
The easiest solution to accessing Heirlooms on alternate servers would simply to make them unlock across your account once purchased, similar to Death Knight creation is enabled when you have a single character at level 55. Due to the possibility of characters returning the initial Heirloom purchase for a refund, the player's account will only update once an Heirloom reaches the non-refundable point. This prevents players from "acquiring" all possible Heirloom items without spending any points.
Throw in a Family Heirloom Chest in all the starter zones and only allow players to withdraw items their account has unlocked -- in a manner similar to the Guild Vendor. If a player has not unlocked an Heirloom, it would not appear in the Chest's "vendor" window.
The Chest would not function in a 1:1 ratio; that is to say, once an Heirloom is unlocked, any number of said item may be withdrawn by any number of characters. You want two Balanced Heartseeker for your Rogue? Fine. You want twenty? Go for it. Heirlooms don't have a vendor value (beyond the initial vendor refund, from which the Chest would be exempt) and cannot be disenchanted, so there's absolutely no profit to be gained from loading down your inventory with excess pieces.
There would be downsides, for both the player and Blizzard, with this approach.
First and foremost, this eliminates the need to grind out the JP/Honor for any given Heirloom piece more than once. That's time spent in dungeons; you pay to play, regardless of what you're doing, and Blizzard likes paying customers. Though the same could be said for the ability to create multiple Death Knight characters across a variety of servers after only reaching level 55 once.
Second, this would mean that players no longer need to transfer characters holding a collection of Heirlooms in order to have these items on a new realm. Naturally, Blizzard would lose out on the occasional $25 character transfer fee. This is somewhat of a moot point, as Blizzard has expressed the desire to enable some form of cross-server transferring of Heirlooms, but I felt that it should be covered nonetheless.
Finally, as for the player, while you would have all your shiny gear on whatever server you decide to play on, you wouldn't start with any enchants on weapons, cloaks, or chest pieces. You'd need to spend time gathering ore/herbs/leather/cloth to sell and work up some cash before outfitting your new Rogue with a pair of +15 Agility enchants. So, despite Blizzard losing the time you would farm up JP/Honor, they now stand to gain the time you spend farming goods to sell.
If Blizzard really wanted to stretch things, they could also include other Account-Bound items that a player may have acquired such as the Onyxian Whelpling and Baby Blizzard Bear, but this idea was mainly meant to focus on Heirloom equipment. Certain Account-Bound items such as Arcanum of Blissful Mending will, naturally, not be available, as you're meant to re-purchase such enchants if needed.
Buying an Heirloom unlocks it for your entire account. New characters can pick up as many as they want immediately after creation, on any realm. No cross-server mail required.
Comments and suggestions are most certainly welcome.