With that many photos you might consider using one of the high end DAM (digital asset management) applications. I use Media Pro 1. It uses catalogs of thumbnails that are linked to the photos on your hard drive, CDs or wherever. A single catalog can hold 250,000 images. It uses Catalog Sets like Events in iPhoto. There are Categories which are like albums in iPhoto. Those and Catalog Sets are virtual. You can batch rename files once in the catalog either by date or text. The folders holding the photos on the hard drive can be set up auto update in the catalog so when you add a photo to the folder it will appear in the catalog. You can add keywords, hierarchical keywords, descriptions, etc. and write them back to the original file.
It has some built in editing capability and versioning capability. Clicking on a keyword will display all photos with that keyword quickly. Searches can be made across multiple catalogs and have the results displayed in a new catalog.
I use it as my primary DAM and iPhoto for special projects like books, etc. The catalogs can be viewed and keywords, descriptions added, etc. without the original files being available. You just can't do any editing, slideshows or anything that requires the full sized file.
OT