I don't recall if it was talked about in the rewards thread, but I was looking at the Double Fine Kickstarter and a couple of things came to mind about why they may have achieved such success and I hope inXile will consider some of it:
1. Progress updates as the campaign went on. Honestly, I'd love to see them write these as updates from Ranger Center being radioed out.
2. Quick videos from the team on reactions to the campaign and what they're looking forward to. Basically, give the PEOPLE behind the game a face and a voice. Not simply, artist, programmer, writer, etc. This would be a really cool, personal touch.
3. Additions to the rewards, to entice people to "upgrade" their tier. I think this may have been a big contributor to DF's success.
4. A "making of" documentary of Wasteland 2, added to some of the tiers.
5. Live Q&A chat with the team