Late this afternoon, Automattic, the folk behind Wordpress released a new theme called Prologue under the GPL that replicates Twitter's look and feel with much of what Twitter already does but with threading via comments. Why it hasn't been done before is a mystery to me although I know of several enterprise projects designed to achieve a similar effect.
Automattic have been really smart by releasing Prologue as a standard theme available at Wordpress.com. People who already have a Wordpress.com account can create another blog and pick up the the theme straightaway. This is the kind of thing that small internal groups will love. The fact the code has been released gives developers with RSS smarts the opportunity to think about how this could be integrated to other internal systems. Will it make any difference to Twitter? I doubt it but it will allow organizations the opportunity to legitimize Twitter style use as an ad hoc communications method.
Mashable takes the view Automattic is 'reinventing the wheel' and talks about limited scenarios for internal Twitter use. I believe that misses an important point. In its current form, Twitter needs a lot more work to make it a secure service. That matters to business people. At least with Wordpress you can take a lot of steps to make sure it is secure behind the firewall. Matthew Ingram has similar thoughts, taking up the idea of distributed networks that are protected against outages.
One thing readers should be aware. Wordpress was never designed to be a large scale CMS so even though it is possible to set up multiple users, it is not truly enterprise class ready. That won't prevent people from experimenting with what I see as a great innovation. Especially when the entry cost is almost zero.