If you're following the latest dev release hold back on upgrading to 1188 until you read this post and check your plugins.
The way options work in the backend has been overhauled. There is now a whitelist for each options page hardcoded in the options page. It's possible to add options to the whitelist if you're developing plugins but unfortunately this means that any old plugin that submits to /wp-admin/options.php will break.
add_option_update_handler($option_group, $option_name, $sanitize_callback = '')
This function adds an option called $option_name to the group(or page) $option_group. Optionally, $sanitize_callback is the name of a function used to sanitize the option value before saving.
remove_option_update_handler($option_group, $option_name, $sanitize_callback = '')
This function removes an option in the same way as above.
There are another two functions,
add_option_whitelist( $new_options, $options = '' ) and
remove_option_whitelist( $del_options, $options = '' ) which are useful for adding and removing options in bulk, but they're mostly for internal use by the first two functions.
See the function
mu_options() in wp-admin/includes/mu.php for an example of usage.