The easiest method to keep your local dev site up to date is to use
drush http://drupal.org/project/drush
This is a command line tool, and if you set up your alias files you
can sync you to dev to live in a couple of commands.
drush sql-drop drush sql-sync @site.live @site.local drush rsync @site.live:%files @site.local:%files
I do this will all my sites and makes my development so much easier.
[Jim replies:] Yes, I believe that drush is the tool/means of choice for such things and these commands are very likely the 'core' of one aspect of what I was trying to describe in the webcast mentioned in this thread.
The more global aspect is "How do I organize and do the full-day workflow of creating and evolving a Drupal site?" And this gets into aspects of more than the core dev-local/remote-live sites. As I am not a drush user much less an expert, I suspect but do not know for sure how the workflow that I've described in my webcast (http://www.sohodojo.biz/sqlyog) could be fully 'drushified' from an automation standpoint to do both the local/remote stuff _and_ the iterative throughout the day development activity covered in my presentation.
I do believe, however, that what is described in the presentation -- taken as a user's spec for what would be useful -- would make for a great drush-based fully Drupal admin feature-set in a contributed module (which I would be happy to collaborate with someone to do).
--Sohodojo Jim--