Running the tests and reading the man page changes again I realized there is an aspect of webrev behavior which might not be obvious: 'webrev -U' will store the webrev to local directory named "webrev" and upload it to remote host with directory name equal to dirname of local workspace/repository.
I think this makes sense since uploading different webrevs to single remote directory named "webrev" is not desired :) The man page was slightly modified to document this behavior. incremental webrev is here: http://cr.opensolaris.org/~vkotal/webrev_upload.onnv.rd3/ final webrev is here: http://cr.opensolaris.org/~vkotal/webrev_upload.onnv.final/ v.