Your updates aren't bad. But what Larian Studios did was a on a completely different level. They had several video updates and while texts may contain more information I am pretty sure that videos will almost always impress more people if they are well done.
The ones from Larian were especially well because they were also funny. So you relinked them just to show your friends a funny video and not only because "look these guys need money for a great game".
The very same goes for other campaigns:
Frontiers: He did small videos about gameplay or just of him while he was explaining stuff (like you also saw with David Braben in the ELITE Updates)
http://www.kickstarter.com/projects/railboy/frontiers-explore-discover-survive/posts
Another great example is Shadowrun Online. They were also struggeling and probably only made the goal because they started to produce several good videos, not about gameplay, but about other stuff, endorsements, or themselves explaining things. That is what you remember from a campaign. Not all the texts.
Shadowrun Online looks very intersting on Kicktraq:
http://www.kicktraq.com/projects/1964352341/shadowrun-online/
To me personally the Deathfire Campaign doesn't seem to be "engaging" enough.
1. As was mentioned before the main video needs to be more catchy, needs to flash people. More Epic music, and more name dropping with some nostalgica coming up. It doesn't help if lots of people visit the site but are not caught be the campaign. The first impression is important. Once they checked out the campaign and decided they won't back it, I am pretty sure most of them wont come back later to see if it improved.
2. The Campaign needs to produce News. Contenwise and viral and in that way engage people. I am very sure that a 10 Minute clip where you explain stuff is much more likely to be shared by people on facebook and taken by news than a plain text.
3. The Campaign needs to be feel more engaging. Give you the impression that you need to participate somehow. Not necessarily by pledging but maybe by using special kickstarter signs, maybe a little contest and so on.
Jagged Alliance Flashback did this to a point where it almost felt being over the top, but thats better than not doing it at all.