So I wanted to correct a few assumptions people are making with this post, I'm biased but will try to stick to facts =p
1. Aion is a grindfest
~ Untrue, aions leveling is a little bit easier than WoWs. I can't comment on raiding and crafting but early crafting is easier than WoW also.
2. Aions graphics are too good to beat WoW in the casual segment with older computers
~ Also untrue, Aion runs much more smoothly than WoW for me on my rig. I have a nice rig but I get 70-100 fps in Aion, I'm lucky to hit 30 in WoW.
3. WoW has been out for many years and is very polished, New mmos are buggy and will fail like age of Conan and warhammer did.
~ Aion has been out for a year in asia, and is very effecient. I haven't noticed any bugs in the game. I played age of conan and the comparison is apples and oranges.
Aion may not be the runaway success people are making it out to be, it may not beat WoW either. There's no question in my mind that the game is better than WoW, but Asian mmo's seem to carry a large stigma and its hard to get people to switch mmo's either way.
Also there remains the question of the dev team and how they deal with hackers//bots//exploits that can't be answered yet for obvious reasons but from its history in asia they have pushed out huge content patches relatively fast and bug free.
Sorry about it being hard to read originally due to formatting