Assuming Aether is Ike's best recovery move, it should work like Zelda's Farore's Wind, where you can control where you move and the more horizontal you move, the less height you gain. This would give Ike a legitimate chance at getting back on the stage without that mysterious magnetism ledge grab that Marth and Roy often employed. To balance it out, the farther sideways you move, the weaker the down slash is.
In any case, it'd be cool if, when using Aether as a recovery move, the sword could catch the side of the stage, like the hookshot and grapple beam, allowing Ike to jump back up.