In Aug this year, Google discontinued developing Wave as a standalone product, however later announced that Wave technology will continue to move forward as an open source project, renamed "Wave in a Box," is aiming to become a server for hosting waves inside a small company or community. With a few extra steps you'll even be able to talk to other wave servers all over world, based on a concept called "federation."
"In past few months, Wave in a Box team made lot of improvements, for instance the panel for viewing waves now supports much more of the functionality from Google Wave, and it looks better and is a lot faster too!
The Robots API has now also been included in Wave in a Box and has most of the functionality available on Google Wave. One of our example robots, Echoey, for Google Wave also works on Wave in a Box. This robot -- as the name might suggest -- echoes whatever is being typed. Due to the realtime nature of Wave, the echoing happens while you type!," stated Google.
The project will be discussed at this week's Wave Summit in San Francisco.
More Info: Wave in a Box website