The Web Desktop Manager component was first released as a free update to BES 4.0 SP6 or later (http://blog.brightpointuk.co.uk/blackberry-web-desktop-manager)

Now the tool has been incorporated into BES 5.0 and enables users to manage their devices directly from the PC web browser (only Internet Explorer 6 or later is supported currently)

The tool is accessed by browsing to https://(BES_Server)/webdesktop:

From this interface users can, provided that the administrator has enabled the feature on the BES itself, edit their default signature as well as message re-direction settings.
Email filters can be created, defining what mails get delivered to the handheld device:

Available filter criteria include:

Which mailbox folders that are synchronised to the handheld device can be defined:

The Contacts that are synchronised to the handheld can be defined, including subfolders of the main Contacts folder:

The contents of the user's handheld device can be backed up to the user's PC via the tool:

Automatic, schedule-based, backups can also be configured:

Should a user be issued with a new device, they can simply connect that device to their PC, once logged into the tool, and switch their account details to the new device automatically: