Wowhead comments on the item would suggest that you can have more than 1 per acct. Good luck!! Per Bliz, the first kill on your account every day has a higher drop % chance for the mount and the 36 slot bag
Oh.... well I'm pure f2p so that ain't gonna fly for long term lol. Anyway, since the previous message, I've gotten two more Haversacks ON MY HORDE ALTS I hate this so much lmfao, I swear if all my horde alts get kitted out and my alli main STILL ain't got that big baggo Imma cut a bitch. I don't even care that I ain't got the horsey yet, it pisses me off that much. BIG BAGGO COME TO MAMA.