The myth of the Next Big Thing has been one of the driving forces of popular entertainment for as long as there have been artists, critics, and paying customers. New album releases give music fans, critics, industry titans, and bloggers a chance to participate in the complex equation of what is "in" and what is "out" in the music world.
Of course, not every new album release is a new album from a new artist. In some cases you have legendary artists continuing to add to their legacy with new music. There's also been the increasingly common and controversial tactic of record companies repackaging older albums and re-releasing them (called "churn"). There are also all those "Greatest Hits" albums that collect the popular songs from popular (and not-so-popular) artists.
Fans looking for New Album releases can turn to industry news outlets like Billboard. There are also a host of upstart web sites and bloggers who do their best to cover the vast number of releases added to store shelves (and digital outlets) every day.