I actually came on today to post about this exact thing. Thanks for commenting, Lylirra! I don't agree with transmogrifying weapons. Armor pieces, though, I can see.
Maybe a blue will see this and can pass it along through the appropriate channels.
Allowing players to visually customize their character's armor beyond just dyes is definitely something we want to do. Feel free to keep debating and discussing how you'd like such a feature implemented, though! For example: would you prefer cosmetic slots or a system like transmogrification in WoW, and why would you prefer one system over another? Etc.
I think cosmetic slots would be better. While it leaves more work for Blizzard (sorry!) it gives me some concerns:
My major concerns about "transmogrifying":
If you want to resell your gear.
It will be more confusing than when a player buys a Skorn only to find it is using the same artwork as The Butcher's Carver, or Inna's Vast Expanse as a Cloth Tunic.
They will make it Bind-to-Account.
So many items are binding in WoW it doesn't matter if you transmogrified one thing into something else. So if I take my best-in-slot item and transmogrify it, it will either become a confusing-looking item in the game or bind to account
which is really dangerous. I say dangerous because it removes good items from the marketplace. Which raises the cost of good items for other players if I ever decide I no longer want to use that item or that character. Higher prices on the market place are not something ANY feature should be trying to achieve. Please do not mistake this as a gold sink.
The lower number of Bind to Account items we can have in this game, the better, I'd like to argue. Especially if you are taking them from the pool of items players can use. Or simply make it these items cannot be sold on the auction house because they have been transmogrified, but are at least tradeable between players. Please, no bind to account transmogrification
The only way I see this being Lore Friendly is giving Shen something like a Horadric Cube (which he should have had instead of this gem crucible the whole time) and call it transmutation, not transmogrification.
If items lose their "transmogrification"/transmutation when they're placed back on the auction house. I would support this feature.
Overall, I support vanity/costume slots over the other feature, though it is (probably) more difficult to code for. Thank you again, Lylirra.