@Andrew Starr-Bochicchio (andrewsomething):
I also am running Ubuntu 12.04 (Precise) and I confirm the crash on 'bzr help tags' and 'bzr help branches'.

Ubuntu bzr package version: 2.5.0-2ubuntu2
Bazaar (bzr) 2.5.0
  Python interpreter: /usr/bin/python 2.7.3
  Python standard library: /usr/lib/python2.7
  Platform: Linux-3.2.0-25-generic-x86_64-with-Ubuntu-12.04-precise
  bzrlib: /usr/lib/python2.7/dist-packages/bzrlib
  Bazaar configuration: /home/cdb/.bazaar
  Bazaar log file: /home/cdb/.bzr.log

Note that "bzr --no-plugins help tags" works fine!!!  Some plugin is causing the issue.
Is there any way to selectively enable or disable plugins one at a time, e.g. with a special command line option?  It would be really painful to uninstall and reinstall all my plugin Ubuntu packages for this test and especially some packages may include multiple actual plugins.

List of plugins:
cdb@svelte:~/.bazaar/plugins$ bzr plugins
bash_completion 2.5.0
  Generate a shell function for bash command line completion.

bzrtools 2.5.0
  Various useful commands for working with bzr.

changelog_merge 2.5.0
  Merge hook for GNU-format ChangeLog files

dbus 0.1.0dev
  D-Bus integration for bzr/bzrlib. 

explorer 1.2.2
  Version Control for Human Beings.

git 0.6.8
  A GIT branch and repository format implementation for bzr.

grep 0.5.0dev
  Print lines matching PATTERN for specified files and revisions.

gtk 0.104.0dev
  Graphical support for Bazaar using GTK.

launchpad 2.5.0
  Launchpad.net integration plugin for Bazaar.

netrc_credential_store 2.5.0
  Use ~/.netrc as a credential store for authentication.conf.

news_merge 2.5.0
  Merge hook for bzr's NEWS file.

po_merge 2.5.0
  Merge hook for ``.po`` files.

qbzr 0.22.2
  QBzr - Qt-based frontend for Bazaar

rewrite 0.6.3
  Rebase support.

svn 1.2.1
  Support for Subversion branches

weave_fmt 2.5.0
  Weave formats.

cdb@svelte:~/.bazaar/plugins$ bzr help tags
bzr: ERROR: exceptions.AttributeError: 'Option' object has no attribute 'get_help_topic'

Traceback (most recent call last):
  File "/usr/lib/python2.7/dist-packages/bzrlib/commands.py", line 920, in exception_to_return_code
    return the_callable(*args, **kwargs)
  File "/usr/lib/python2.7/dist-packages/bzrlib/commands.py", line 1131, in run_bzr
    ret = run(*run_argv)
  File "/usr/lib/python2.7/dist-packages/bzrlib/commands.py", line 673, in run_argv_aliases
    return self.run(**all_cmd_args)
  File "/usr/lib/python2.7/dist-packages/bzrlib/commands.py", line 695, in run
    return self._operation.run_simple(*args, **kwargs)
  File "/usr/lib/python2.7/dist-packages/bzrlib/cleanup.py", line 136, in run_simple
    self.cleanups, self.func, *args, **kwargs)
  File "/usr/lib/python2.7/dist-packages/bzrlib/cleanup.py", line 166, in _do_with_cleanups
    result = func(*args, **kwargs)
  File "/usr/lib/python2.7/dist-packages/bzrlib/commands.py", line 1148, in ignore_pipe
    result = func(*args, **kwargs)
  File "/usr/lib/python2.7/dist-packages/bzrlib/builtins.py", line 4819, in run
    bzrlib.help.help(topic)
  File "/usr/lib/python2.7/dist-packages/bzrlib/help.py", line 51, in help
    topic_obj.get_help_topic()))
AttributeError: 'Option' object has no attribute 'get_help_topic'