The docs say
appcfg.py --dump --app_id=<app-id> \
--url=http://<appname>.appspot.com/remote_api \
--filename=<data-filename>
The thing itself barfs:
Usage: appcfg.py [options] <action>
appcfg.py: error: no such option: --dump
$ cat /usr/local/share/google_appengine/VERSION
release: "1.3.4"
Thoughts?