This is my take on this whole subject.Ten years is a long time right?Well in that time I doubt the Jedi are going to forget about the Sith encounter they had.So they will probally be in search of them.The movie could start out with the Jedi already having knowledge of Sidious' new apprentice.That would be very interesting.
Yes I've always thought that too! There was going to be one in TPM, but GL thought it was "too scary." Seeing as Episode 2 is meant to be darker we could certainly see a Sith Witch. Aurra Sing was meant to be a Jedi apprentice at one point and so she must have force powers. Perhaps she somehow becomes the apprentice of Sidious.