After 1 Blood Seeker 16 hours of camping I was pretty bored and wanted to make a quick circle around deepholm to check for possible corpse etc. and I found Aeonaxx! My hands were shaking because it was so far away and if I was just 1-2 second slower I would have not gotten it.
Good luck for everyone and I feel very sorry for couple of people who had been camping it for months and missed it many times. :'(
Here is a screenie I almost forgot to take:
Drops the Reins of the Phosphorescent Stone Drake, a rare purple stone drake mount.
Aeonaxx has the chance of spawning every 6-22 hours.