Keeping development database in sync with production database
It really depends on what you're changing in the development environment. If you're adding/removing modules, content types, custom fields, etc.. I can't think of a really good way to do this in any sort of trustworthy automated way.  

Also I am SURE there must be modules for exporting Drupal content.  A quick search turned this up: http://drupal.org/project/node_export