"It's like, okay, Obi-Wan was dead when episode four started, so maybe everyone thinks I'm dead and we'll find out what happened to Mace Windu," says Jackson. "I can come back as one-armed or a one-handed Jedi that's still around that didn't actually die."

If Disney's not down for an actual appearance, Jackson's flexible. "I could do that or be a ghost hologram. I don't care," Jackson quipped. "I just want to stay associated with the franchise. Not that I won't because I've been in three of them."

Oh hell yeah!

Source: http://www.eonline.com/news/369775/star-wars-7-samuel-l-jackson-says-quot-hell-yeah-quot-to-returning-as-mace-windu-mdash-even-as-a-one-armed-ghost

Well this guy was pushed out of the window by the force of the emperor. I see the possibility of an experienced jedi surviving the fall and managing to land softly using the force. 

Me too!

Or if they don't want to do that, a hologram or ghost is fine with me.

Bring back Mace Windu!!!