The rumored Google Music service will launch in the fourth quarter, according to tech blog Gizmodo, which cited an interview with Google's Android product manager Gaurav Jain in an Israeli newspaper.

The Q4 launch would correspond with that of the new Android 3.0 mobile phone operating system, which would make sense seeing as cloud-based access to music files from mobile phones is a central element of the Google Music plan.

This comes on the heels of Boy Genius Report's prediction that Apple will launch its iTunes-in-the-clouds service later this year as well, according to “reliable Apple sources.” And all of it follows the recent market entry of smaller competitors already offering cloud-based music-locker-like streaming services such as mSpot, MP3Tunes.

Google and Apple have massive marketing bullhorns and having them both loudly blaring a cloud-music message in competition with each other during the lucrative holiday sales season could do loads to help shift the public's understanding of this new music distribution model.