One of the new tweaks going into (mega)patch 3.2 is more mailboxes for the old capital cities.
I suspect this is nothing to do with my suggestion, in fact I can’t even remember when I posted this (I suspect it was when I was levelling inscription on my Death Knight alt, all that running around from mailbox to auction house can’t be healthy!). I’d always assumed that no one from Blizzard actually read the suggestions forum and it was more a way to just get things off your chest. But … you never know.
Welcome to Spinksville! 
The idea that too much running isn’t healthy…
That just makes me laugh. 🙂
You’ll regret that when my poor death knight keels over from exhaustion 🙂 Apart from the fact that it’s dead already …