dunno if this has been posted before but in the official german WordPress support forums there's been some questions where the entry IDs in the 'Manage Posts/Pages' view are gone.. obviously they've been removed cause most common users dont need them..
However, for advanced WordPress Users/ developers those IDs were quite interesting for some plugins or template tags.
What this plugin does is to add a new column to the ‘Manage Posts’ and ‘Manage Pages’ view, with the entry’s ID, as it was in versions prior to 2.5.
Download, Screenshot & Infos at: http://www.schloebe.de/wordpress/manage-posts-pages-id-25/#english
(Hope there's not been published a similar plugin already ;-))