I'm betting he's hardly in it at all and the original stuff about him being lost is close to the mark, they find him and that's the cliffhangar making you want more at the end of the film.
Killing Luke would be a very bold move early on and without him having an epic out would wee all over the original films. I think they have to do it just not this early. Luke was always destined to be this hugely powerful new hope. They have to show him fulfilling some of that potential and then kill him. They can't really keep him around too long with the new look otherwise you just say to yourself why doesn't luke go do it. I am hoping they kill Han as I have said multiple times in this thread, such a shallow over hyped character of nothing. If Han get's it I think I will cheer in the cinema.
![Wink ;) ;)](/styles/default/xenforo/vbSmilies/Normal/wink.gif)
Luke will die at the end of the trilogy is where my money is.