I've just released a plugin which replicates the custom column feature of the manage posts page. This is in response to the long-standing enhancement request. It provides a manage_pages_custom_column action and manage_pages_columns filter which can be used similarly to the manage_posts_custom_column action and manage_posts_columns filter provided by WordPress.
This plugin is of particular interest to plugin developers, who can use the hooks it provides to give their users information on the manage pages screen.
I’ve also written a tutorial on how to add custom columns to the manage posts screen which also applies to these hooks.