CNet reports that Google has launched a new Google Music search service which allows users to type in band names, albums and songs into Google which will bring relevant results along with links to merchants for online ordering or downloading.
Apple's iTunes is amongst the initial merchant partners along with RealNetworks, eMusic and Amazon.com
This confirms a Google and Apple rumor from August 2005 that claimed that "Google is going to offer iTunes somehow on their platform".
The new system appears to be in place (samples: Tanya Donelly, Crash Test Dummies)