So, thinking about the excellent points made by both Geoff and Roderick - it would be good to identify a number of key questions that form the basis for an event of some sort. Clearly we are all coming from a similar direction; having concerns about 'what Illustration is', its role and the drivers for its production.
Geoff talks about the disadvantages that diversity of approach brings - it can make Illustrative practice seem unwieldy and vague. However it may be worth looking at this in relation to a critical framework for the subject [if, indeed, it is necessary] in a totally different way. In other words to remove it from the academic and locate it in the 'real' world. If we were to suggest that the Illustration is the artwork in its mediated form [print/screen etc] we could back peddle and look at why it exists in that form. Who commissions it? I can hear the collective groans - not another discussion that descends in to endless bellyaching about clients misunderstanding and mistreatment of Illustrators. No, that is not what I am saying - but I would suggest that if we are to suggest a critical framework for the subject we should consider commerce.
Rod, you have eloquently approached the relationship between technological development in media and the evolution of the subject. Some of the opportunities that technology, the web and new media offer, bypass the traditional role of client and Illustrator. This is interesting when considering the subject because, increasingly, Illustrators are trading off their ability to generate content. Illustrators becoming auteurs? Illustrator becomes client?
It is interesting to consider how this affects the 'discipline' of Illustration.
Much has been made of the lack of editorial control over content online. Previously that control came through conventional roles within media organisations but the ease with which work can be published has removed the need to negotiate an appropriate solution to a visual problem. The editor has been bypassed. It is possible in this scenario that the 'discipline' can be eroded. We are also witnessing a shift in the nature and role of commerce.
So, the realm of commerce forms part of the critical framework that Illustration inhabits. I suppose then the difficulty is shaping this monumental territory in to something navigable - not easy!
One way may be to dis-aggregate the territory, think about types of work and types of client. [Alan Male in Illustration; a critical and theoretical perspective talks about 5 key types of Illustration - this may be an interesting start point?]