I had the down-the-road thought just now that I wanted to put into circulation before I forgot about it.
One of the challenges that we will face in developing open source Wave is that Google and others - but mostly Google - are out there using operational transform technologies also. So far the Google Drive Realtime API hasn't had much impact, but it's being "demoed" successfully in Drive apps like Docs and Presentations. The advantages of an open source Wave implementation are, of course, that people can own their own data and identity management without having to rely on a specific vendor's infrastructure. But the flip side of that is that you have to look carefully at infrastructure that integrates OT and understand what you have to do similarly to showcase your technologies. That brings me to OpenOffice. At some point it will be beneficial to consider how the Wave API can enable apps in the OpenOffice suite to take advantage of OT technologies in Wave and its other various features. In fact, it's not unthinkable that an OpenOffice for Wave variant might not be feasible at some point, maintaining a familiar office automation paradigm as a user interface for those who relate to that sort of tool but having the power of Wave to drive collaborative document editing, comments, embedded apps and so on, with Wave data structures underneath the OO interface. Just idle thoughts for now, but if we make good progress over the next several months, it's a sub-project that may help to attract more developers to Wave technologies. All the best, John Blossom