This is great news for collectors everywhere, getting tabards, heirlooms and toy items moved to something like a pet or mount interface would be amazing, and free up a ton of bag space.
Bashiok's response was actually in a thread discussing cross-realm heirlooms, so perhaps this is a system which would move heirlooms to a battle.net account level, like mounts and pets, where they would be universally accessible from any character, regardless of server. If the same were true for toys, I think a few collectors would be a little sad, but nonetheless it would make it a lot easier to remember where your puntable marmot had gone. As Adam said in our work chat, "I'll immediately have 100+ free bag slots if they do that"! Just having an heirloom interface that was genuinely account-wide rather than server based would be amazing.