If you remember from the new trailer, the man talking who is rumored to be Luke says,
"The Force is strong in my family. My father has it. I have it. My sister has it. You have that power, too."
Now why would he say that? Anakin is alive not Darth, Anakin. Even though that last scene from Star Wars Episode VI might suggest otherwise, there is probably new ways to bring people back after 30 years or they might just decide, "that ending sucked, lets let him live." This would give many new possibilities for the movie and sequels. If he was resurrected, they could keep prequel Anakin (who I loved, bring the hate) and the villain could be revealed as Anakin at the end which would explain the mechanical hand with R-2. If the executives ignored the ghost Ani (yeah, I called him Ani hate me) it would be a great way for the Sith not to like the new characters.