you do get multiple saddles if you are also logged in on your other WoW account when you get the saddle on your main account. Keep in mind tho that the saddle you receive is Soulbound, and requires level 90 to be used. I've bought a Battlechest for the box, and I figured that I would activate the account to receive multiple saddles, since my friend told me that it worked for him, who shares the same bnet account with his brother. I did not knew though that it has a level requirement (they both had max level characters), so now I have to grind to level 90 if I want the extra mount.