Indexing sites have become somewhat of a necessity these days, due to the deluge of passworded/trojaned spam in all the groups that make manual header downloading a giant PITA. This is a niche that Alt.Binz, with its built-in search engines and no header support, occupies quite comfortably at the moment.
But if all the sites start being hammered, I guess we'll start to see more 'local', decentralised solutions. Desktop indexing FTW!