The long-awaited Google Music service should arrive later this week at Google's Spinal Tap-inspired event, but if Cnet is to be believed, it'll launch without two of the biggest players in the US music industry. Sony and Warner will not be posting any of their artists on the new MP3 store, putting it at a major disadvantage to iTunes and other digital music vendors. The other two major labels, EMI and Universal, will be selling music through Google.