Google announced the existence of Magnifier via its blog, describing it as "a new music discovery site." It features interviews with artists and bands, as well as free music you can add to your Music Beta account daily (you need to be a user in order to score the tracks).
Looking at the site, we're hard-pressed to picture anyone using it, aside from Google fans that are also passive music listeners. There's already a ton of stellar free music blogs/services (see RCRD LBL, MySpoonful and Epitonic) who have been in the music writing/curating game for much longer than Google. They also offer a larger quantity of more varied songs (which you can download and upload to your locker). Granted, it might be easier to add music to the service directly from Magnifier, seeing how it's plugged into the service.
Moreover, a few random free songs per day doesn't seem like much when compared to the buffet of music that can be consumed on true subscription services like Spotify and Rdio. Yes, the curation aspect is certainly appealing, but when it comes down to it, I would rather listen to an entire My Morning Jacket album, not just one song.