Java is still hot, and announcements of digitally signed Java applets and OS level support by all vendors are major steps. However, persistence and collaboration interested me more at this conference.
Technical papers on cacheing proxy servers were very informative, and getting more and more important.
Content negotiation is another hot issue, for the HTTP standard. Content document types, like PDF vs HTML are most important, with language for internationalization coming next. Bandwidth negotiation is very important, but the standard is still too far off.
The URN committee, which I said last year "can also be safely ignored as 'not sufficient for clear, useful meaning'" has been disbanded. Different approaches are now being tried for persistence of data, which is still an important issue, but I think the realization is coming that it's a process issue that organizations have to step up to if they care about their data being available through re-organizations and personnel changes, not something that technology can solve.
Microsoft probably had the strongest corporate showing this year, with representatives on all the important panels. Quite a change. They still made some mistakes, but are getting much more clueful. Netscape also had good representation.