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.
Damn, that was so freaking easy to understand that Google Wave wasn't a product with a clear purpose. It wasn't solving any single problem. I was really surprised to see Google coming up with this product, where Product Management is taken into such high levels. Anyways, no regrets, hopefully it'll free up some space for something worth trying.