It looks like using CouchDB with the standard web2py DAL is still a ways off:
I’m working on using CouchDB from web2py. python-couchdb looks fairly powerful and well designed but not particularly well documented. Does anybody have good examples of using CouchDB from in a DAL-like way? The best I’ve found is this blog entry by David Watson, but it doesn’t go into much depth. I’m looking for more.
Alternatively, I’ll accept information about the status of CouchDB in web2py that is more recent.
Look into the file gluon/contrib/gql.py which overrides the DAL to work on GAE. couchdb would work very much the same. we have one partial implementation of MondoDB support. We have solved the problem of uuid vs autoincrement integer id. Joins us on the web2py mailing list to discuss more.