Another way that one can submit changes to Drupal with Bazaar-NG is by generating a diff. Diffs are a little bit more awkward to work with, but do fit well within the current system.
You can generate a diff against another branch at any time by using the bzr diff command. For example, to generate a diff against the official Drupal development tree, one would run:
$ cd my-drupal-branch
$ bzr diff -r branch:http://bzr.drupal.org > ~/mypatch
One important note though! Make sure that you merge from the official drupal branch and commit before you generate your diff! Otherwise, bzr will think that you mean for the changes in official drupal development should be reverted!
If you find it a pain in the rear to constantly have to type so much whenever you want a diff, then consider putting the following line in your ~/.bashrc. The next time that you run in, you can compare the differences in your branches against official drupal whenever you want by running "ddiff":
alias ddiff='bzr diff -r branch:http://drupal.revisioncontrol.net/core/head"
To get function names into your diff, use
--diff-options -F^f. If you are lazy/efficient, you might alias the 'b' command to
bzr diff --diff-options -F^f . > patch