One critical question is whether Google will successfully define the Wave client/server (GWT-based) protocol in an open fashion, or at least open enough that pe

One critical question is whether Google will successfully define the Wave client/server (GWT-based) protocol in an open fashion, or at least open enough that people can implement their own. Otherwise, the whole thing will be dependent on the quality of their client/server, and people will still be locked into a single implementation. And, the other issue is just how extensible their data model can be, for other clients to do more than just their simplistic pidgin-HTML document rendering model. I.e., can another client/server pair use a more sophisticated document model but still have the document maintained by other implementations? (Not talking about robots or gadgets here, but a more fundamental question of document extensibility. On these questions (and others) hang the whole general utility of the collaborative document editing facility.