Spotify is coming soon to the iPhone, iPad and iPod Touch. Before you say "But it's already there ..." consider this: Spotify announced is Spotify API called libspotify 9, which means that a Spotify embedded player can be used in a variety of ways.
"Today we are announcing a great addition to the Spotify Platform. The Spotify Embedded Player libspotify 9 is now available for iOS," reads the post on the Spotify blog.
Why should you care? Now there will be a number of Spotify apps that will spring up from developers, bringing with them a number of new ways to use Spotify on the iPhone, iPad and iPod Touch. This could be best used a sideshow to an app that's dedicated to another purpose, but I'm sure people will create dedicated Spotify apps to do various things within Spotify itself.
Check out more about steaming music sites in the Spacelab Streaming Music Guide.