I'll just second the comment that you're now fighting perceptions and even heading towards damage control - a few people that I spoke to recently (at a random social gathering) who are pretty influential in Australian fandom were not happy at the apparent lack of progress and non-responsiveness of the committee - to the point of suggesting that "conjecture" might turn out to be an appropriate name. There was also some grumbling about how a troubled Natcon 2009 could impact WorldCon 2010, because it's working on a longer lead-time and needs a bit of momentum among fandom to keep moving.
See also this post by Sean Williams almost a month ago, and the 82 comments on it.
e.g. quoting angriest : It's sad, but it's just one of those thing - I'm not in a position to drop the cash for a trip to Adelaide, the accomodation, the memberships, etc, at the last minute, and I'm unconvinced at this stage that the convention's going to happen.
and Absolutely. There's a bunch of stuff that sets off alarm bells, not so much a lack of confirmed guests so much as:

- no outlet to supply program items.
- no obvious theme/program overview/etc.
- no list of committee members.
- no obvious means of directly communicating with the convention committee.