Apparently, this is the story: Ridley Scott is in charge and Damon Lindelof (of lost fame) is going to rewrite the script. Why it needed rewriting, isn't really discussed. Having grasped the basics of Lost (I was not an avid watcher) there should be some interesting plot turns. Wonder if there will be any Dharma beer popping up.
I have one problem with prequels. They normally suck. Now if he comes up with a really good script that explains how everyone was chosen and how they met the alien in the first place, that would OK. Especially if you have the urge to scream out NO DON'T GO THERE! knowing they'll go anyway.
Personally, I'd like to see Alien redone in 3D. But that's just me.