Anyone who wants to learn about Debian should also learn about Ubuntu at the same time, and my talk is subtitled "An outsider's perspective on Ubuntu and Debian." If you are shooting very low and assume no one knows anything about Debian, or even computers, etc. then maybe my talk isn't relevant, but I doubt that many such people would randomly show up to Edinburgh. Furthermore, I see no talks on how to install Debian, walkthroughs of Etch features, so maybe that is an old version of that day's motto--this is your 7th conference.
I suspect a fair number of people want to know more details about Debian, and how it relates to Ubuntu, and my talk is the only one discussing this, and should be understandable by non-developers. I can focus on that even more: I assume people know what
X.org means, but I can assume less if anyone wanted me to. I suggested Debian Day because It is the day when your partners and others will be there, and I think it might be good for a slightly more diverse audience to be aware of these issues. I try to catalog a lot of them in a concise package. FWIW, I think of this talk as much more appropriate for a Debian conference than an Ubuntu conference.
-Keith