Ian McDairmid seems fairly confident Emperor Palpatine won't be in The Force Awakens. Here's some paragraphs that have been running around the internet all day where he appears to confirm he hasn't had the call up. Yet.
“There’s been all sorts of rumors. No conversations have been had, and no deals have been struck. And anyway, I’m dead…but I could be resurrected. Yes, I’ve heard of ghosts, I’ve heard of clones. There’s all sorts of possibilities. But until I get that phone call, like the one I had before, I won’t believe I’m in it. And I think I won’t be working for it, because it’s a whole new world now that I think is going to be invented.
There might be some old favorites in it, but I should imagine it’s about the adventures of the descendents of the first characters and new villains that no one except George has ever imagined. And I hope it is, because the great thing about Disney is that it will continue in a new form with new people and be reinvented, just like all great works of art are sooner of later.”
I think McDairmid is on the money. Episode 7 will set up the new generation of characters and the old will pass the torch to the new. 8 and 9 will be wholly original. This is not a new hope....