As we announced in August 2010, we are not continuing active development of Google Wave as a stand-alone product. Google Wave will be shut down in April 2012. This page details the implication of the turn down process for Google Wave. Stage 1: Google Wave is read-only -- January 31, 2012 In this stage, you will no longer be able to create or edit waves.
As of July 2012, Google Notebook has shut down and all Notebook data should now be in Google Docs.