Adding example command from Drupalcon Advanced Drush session http://chicago2011.drupal.org/sessions/advanced-drush

drush xkcd:
A command line tool (1) for a web site tool (2), that emulates
(badly) a web based tool (3) that emulates (badly) a command line tool (4) to
access a web site (5) with awesome geek humor.\n
(1) Drush
(2) Drupal
(3) http://uni.xkcd.com/
(4) BASH
(5) http://xkcd.com/

#1011260 by greg.1.anderson: Unify command help so that help options do not begin with '--' in command help.

#1010984 by greg.1.anderson: Allow aliases to define command-specific options that only apply when alias is used as source or target of rsync / sql-sync

#1008118 by greg.1.anderson: Standardize on 'return drush_user_abort();' as correct way to stop execution when user cancels

Add a warning for Windows users. Includes instructions for finding more information  and for disabling the warning. We need a Windows co-maintainer to resolve the listed issues so we can remove the warning. Feedback welcome about the nag text and disable process.