orion90000
First Post
Treating it similarly to a Phase Spider's ability; it takes a move action to cast, but the teleportation is still as instantaneous as a Phase Spider phasing.
Teleport has a casting time of "1 standard action" not move action. The phase spider goes from ethereal to material as a free action.
Ethereal Jaunt (Su)
A phase spider can shift from the Ethereal Plane to the Material Plane as a free action, and shift back again as a move action (or during a move action). The ability is otherwise identical with ethereal jaunt (caster level 15th).
That's why I would rule that if it were a free action then I would allow the character to sneak attack. If it is a standard action then opponent would get to take another action before being attacked, thus denying the rogue a sneak attack unless the rogue was undetectable in some fashion (invisible, stealthed, etc).