A nice feature in Lightroom is "smart collections", which are collections that automatically include images based on some criteria, such as keywords, file extension, rating, etc. As images are imported into the catalog, the appropriate images are automatically added to the smart collections.
We've looked at that sort of feature, and we may work it in to future updates.
Thanks for the reply. Although I am not a big fan or user of Lightroom, I had been using it to catalog my images and found smart collections to be very useful.