Coins from the Nether

I had a slight Brewfest "oops" last night. While I was busy shuttling barrels, my number of Brewfest tokens ticked past the 200 mark, and I got a message saying there was no room in my inventory. Whoops.

When I checked into Ironforge a few minutes later, I found this waiting for me in my mailbox:

Anyone know how long this has been in the game? It's the first time I've come across it, and I know it didn't use to be there…

Nice touch, though. :)