The only episode 7 news out of the D23 Expo was the lack of news from “Star War: Episode VII.” The fans booed Walt Disney Studios chairman Alan Horn when he said:
“I do wish I could tell you more but there are dark forces. And they are watching.”
But then came a rumor that actor Ian McDiarmid was to return as Palpatine.
McDiarmid played Emperor Palpatine in the original trilogy and Supreme Chancellor Palpatine in the prequels. As you know in “Return of the Jedi” the Emperor dies, so it was kind of shocking that he will return.He may come back as a clone, like in the comic books.
According tothe source, he does come back. Here is what was said.
Palpatine comes back as a Force Ghost..like Obi Wan. (Sith Lords learned similar techniques, which in some cases allowed them to physically interact with their environment.)
Source
Latino Review