If you’ve not, you must now upgrade to WordPress 2.8.1. This upgrade fixes many bugs and tightens security for plugin administration pages, that could be viewed by unprivileged users, resulting in information being leaked. Not all plugins are vulnerable to this problem. Apart from this dashboard memory usage is reduced, the automatic upgrade no longer accidentally deletes files when cleaning up from a failed upgrade. Full details on what has been updated are here.
Download: WordPress 2.8.1