Unlike a traditional wand that holds 50 charges, an eternal wand allows any character who can cast arcane spells to use the spell contained in it 3 times a day.
Okay, the assassin in my group is excited by this, since he reckons this allows him to use a shocking grasp eternal wand to make touch sneak attacks. (due to the "any character who can cast arcane spells" bit)
Sounds correct. The description of the item refers to magewrights using the wands to cast offensive spells which they can't normally, so it seems like you don't need to have the spell contained in the wand on your spell list to use it.
