I stumpled upon this Cnet article in which it is stated that, at the National Association of Recording Merchandisers, Chris Sacca, head of business development for Google, revealed:

We are not going to be selling music

For over a year, many facts have been unveiled to prove that Google was indeed going to open a music store, and this is only an example taken from an article on Cnet blog:

The most recent evidence is adding “/music” to google.com’s robots.txt file, meaning that such a subdirectory is expected to be created any time.
We also noticed this odd behavior earlier today. No “google.com/music” Web site exists on the public Internet. But searching Google’s index for “google.com/music” yields a different result than the standard “Sorry, no information is available for the URL” error message. - Declan McCullagh

Would I want Google to open a webbased music store? Honestly, I do not think this would change my life at all. In fact I am not so much into buying music. Don’t get me wrong I’m not downloading much either. In fact, I just stream it from Yahoo! Music Unllimited.
Some say they really care about owning the music. Some say they would never buy music online but would rather get a CD to own the music “for real” (?).