The Workshop abstract correctly notes that, although Unicode will be the basic character set in the next version of HTML, internationalization is more than just a character set.
For the past year or so I have been developing new Macintosh language kits for South and Southeast Asia. The scripts used in these regions present some of the greatest challenges for text presentation. They also clearly illustrate why the original Unicode text model assumed a sharp distinction between the content of text (character) and its form (glyph). Where complex scripts such as these are concerned, a standard for rich line layout that follows the Unicode text model will be necessary if we are to see the benefits of adopting Unicode on the web.
I am quite familar with Unicode, since I wrote the original Unicode Principles in 1989. I am less familiar with internationalization issues on the Web and hope to learn more.