It seems like it's only a matter of time, especially with account achievements and such. It seems like Blizzard is really pushing for this idea of 'the player got the achievement/mount/pet/title; the character they got it on is irrelevent'.
Besides, it doesn't make sense to have to farm for a mount on 10 different toons - isn't once enough?
'What other people think of me is none of my business" - RuPaul
Psure blizz has wanted to do it for a long time is just a matter of getting the time to code it. Because it would take alot of effort and dev time to make it happen. I would perf they fix up race models before they do this because they need it alot more.
Yep I've hear they want to make the pets accountbound and I thought I've heard they think of doing this with mounts aswell. They've said something at Blizzcon didn't they?