The SharePoint team has recently announced the release of an Infrastructure Update for Microsoft Office Servers (KB951297). This update includes Enterprise Search improvements for SharePoint Server 2007. To me, the initial "wow factor" comes from the Federated Search capability and a search administration dashboard. The user interface of both components seemlessly fits into existing installations and can add real value with very little effort.
Search Adminstration Dashboard:
Federated Search Results in an existing SharePoint Search Center (edit mode):
Federated Search Results in an existing SharePoint Search Center (published):
Amongst other things, the update allows results from search providers that conform to the OpenSearch standard to be displayed on a SharePoint page (as shown above). This means that when a user performs a search not only will they be shown content stored in SharePoint, file systems and possibly LOB applications but they will also see results from their favourite websites (e.g. Live.com, Wikipedia and TechNet!). Multiple search providers can also be displayed on a single page, allowing users to view search results from numerous locations.
From an admin perspective it is really simple to add federated locations (Central Admin> SSP >Search Administation > Federated Locations > New Location). A 'Federated Results' Web Part can then be added to a page and very easily configured to show results from a particular federated location.
More information can be found here.