Coleman, (Google Wave Team) says
We recently made it possible to export a single wave as a Zip file. Now, you can now also select up to 10 waves in your search panel and download them all together as a set of PDFs.
We hope this feature proves a useful way of saving the information that you have in waves. For more information on it, please visit the help center article.
In addition, we're working on ways for you to access waves through Google Docs and as we announced back in August, we'll continue to keep wave.google.com running at least through the end of the year.