I think any game related to The Dig, be it fan made or LucasArts made, would have to retain the feeling of a desolate, uninhabited and ancient place. That is one of the most unique and interesting aspects to the original game. You're stuck on some planet (or whatever), and you have no idea where it is, who lived there, why you are there and how you can get back home. It's magical, mystical and monumental, and totally beyond your comprehension.
If any sequel were to be set in a place any different from that, it just wouldn't be The Dig. To me, anyway... what do others think? (I'm bouncing my idea