I understand the 4.3 PTR just went live, and that there's a whole slew of new class balance changes and dungeon screenshots and achievements and spell icons and and and BUT THIS IS MORE IMPORTANT.
With people collecting gear for Transmogrification and 4.3's Void Storage tantalizingly close but not here yet, bag space has become an invaluable commodity. Yesterday I decided to finally upgrade Rades' bags, and made quite possibly THE MOST AMAZING DISCOVERY OF ALL TIME.
Note: I feel I should point out that I'm not saying this is anything new! But it was new, WONDERFUL, GLORIOUS news to me! ;)
I have no idea how long you've been able to do this. But judging from the reactions on Twitter when I started raving about this discovery, there's plenty of other players who didn't know about it either! SO NOW YOU KNOW! :D