google wave is going to be shut down by the end of the year:

»wave has not seen the user adoption we would have liked. we don’t plan to continue developing wave as a standalone product, but we will maintain the site at least through the end of the year and extend the technology for use in other google projects [...] we will work on tools so that users can easily “liberate” their content from wave.«

if you think that google wave should be saved join the cause: savegooglewave.com and retweet