Torrentz was a site that didn't host files itself; it instead acted as a search engine, directing people to sites like kat or piratebay. Before it shut down (a week ago, stopped indexing everything, even if the domain still lives), it was 186 on web-ranking service Alexa, putting it ahead of sites like Flickr.
And as happens in every torrent site, for one down, five clones are up. In this case, a new clone site is online at torrentz2.eu, indexing lots of stuff from different sources.
But it is not the only one. For example these is another site called "Torrent Search Engine" and does the same work. Find it at torrentsearchengine.altervista.org.