I wonder what the server and bandwidth specs would need to be to host your own system.
And would companies be happy with their employees collaborating with other companies employees, even if they're a trusted partner, if the data has to go through the Google server? There was some mention during the Federation part of the video about private replies and them not going to the Google servers, but I'm not sure whether that was just because the private replies were between two people on the same private Wave system.