Still the Best for Searching
Coveo are still the number one providers of search engines for SharePoint. With the limitations for searching in SharePoint 2003 Coveo was a must and I used it had many of the installation I did. Now with SharePoint 2007 Enterprise Search things have moved forward, but Coveo still brings a lot more to the party and is the most intelligent Searching application for SharePoint.
Perhaps now aimed more at the bigger companies.