The current plan is to have a separate set of demonstrations and
tutorials with a number of public machines showing how to install
debian/etc. Such demonstrations don't really lend themselves well to a
large talk format. Again, see previous comments on scheduling.
Which is why your conference rooms will be available for you to discuss other things.
Anyway, I have no idea who all is involved in this decision, but I just feel that when you invite someone, it is cruel when you change your mind at the last minute, and that is why I am appealing. Imagine you get invited to a date with a hot girl and you show up to her house and she says that it was an administrative mistake and she wasn't really interested. Except in that case, you wouldn't have made a presentation and bought a plane ticket.
Whether my paper is perfect is almost a secondary issue. The person who invites people should realize this situation and I'd rather not have to re-explain to 100 different people why my talk to might be relevant to a Debian conference because I did this last November.
I personally think that this mistake happened should have been conveyed to me in private. (If I even thought I had been rejected, I wouldn't have e-mailed this list. I had e-mailed Joerg Jaspert multiple times, but was getting anxious as it is so last minute.)
Even if I did talk now, I'd know that 100s people know I shouldn't be there. If only the person who made the decision knew the whole truth, I'd feel a lot more welcome. :-)
-Keith