I think his main improvement to Twitter is not debatable at all - being able to host your own and determining who can join and who can't - is key for microblogg

I think his main improvement to Twitter is not debatable at all - being able to host your own and determining who can join and who can't - is key for microblogging like this to really take off. Twitter has shown the world that microblogging can be tremendously useful. Most businesses, however, will not use it if everyone can see what their employees are posting. Not to mention that a lot of businesses I know simply feel uncomfortable if they don't in some way own the servers that run stuff that's important to them.