I don't think anyone is sure, I guess we'll find out when the list comes out with all the people who win the qualifiers. When Deno came out with the thread 'Mandatory is mandatory", it could have meant all those that did not show for the KOH event. That included Paul Potier (in Japan for another tournament), Santos, who was in the Philipines, 3 Australians, and 2 Europeans. If they were like Ronnie O'Sullivan and got prior permission, then it may come down to people who got excused for health reasons - possibly Buddy Hall and Ed Kelly, etc.? Those are just my speculations. I can't think anyone would really give up their spot, because this is going to be one of the most enjoyable tours in their careers, with an automatic payday.
I'm not really sure why they changed the N. American and World tournies to the 1st and 2nd events, instead of the 2 members-only events like it was originally.
It does seem stange. Maybe because of the present delay they might not be able to play all the tourneys this year and they want to make sure the open tourneys are played ? This means that they will have to secure 25 more venues for qualifiers for those tournaments before the first event can even be held. Already, we are looking into March for the first one, and if they have to get 50 more qualified players, that could run well into April or May, which will jam all 5 of the events (including the qualifier for 2007 tour) into the latter half of the year, making it more difficult not to conflict with other events. Most of May is committed to league nationals in Vegas for a lot of players who don't want to let their teams down, so I hope they don't try to schedule then.
IMHO, I think this makes it anti-climactic as well, as I think having the first 2 member-only events, then building for the N. American, then culminating in the Worlds builds excitement and gives them the time to get the spots filled.
I know they are working around the clock to secure sites, produce tv, line up all the minutiae, etc., but having someone dedicated to dispense information in bigger doses and more frequently would help us all schedule our lives, because in 2006, our lives are centered around the IPT. .
I,m sure the changes and lack of info are causing many players difficulties and extra cost. ie if you want low cost airfare, you have to book well in advance. Booking late [ if you can get a flight] is expensive. 
Telling us up front who is not in anymore (because we are going to know anyway eventually), telling us when they changed the schedule on the website from the 2 members-only events first, etc. leads to better communication and puts speculation, rumors and innuendoes to rest. (Is the cloth going to be changed to slower cloth? Are the balls going to be changed to use a heavier cueball? Are the pockets going to be shimmed tighter?

These are all concerns, as a lot of members are trying to get their tables to these specs to be able to practice on.) This is not criticism, but merely a suggestion on how it could run smoother. Trust me, I know the headaches of business and tour startups!