Google Music launched in Europe about a month ago, and when it arrived it did so with a feature that was not available for US-based users. That feature was music scanning and matching and in fact, it remained unavailable for US users until today. Simply put, Google has officially announced that those in the US now have access to music matching.
This feature should make things easier for those just getting started with Google Music. After all, with matching you now have the potential for faster upload times. Well, faster set-up times may be more accurate as the matching can potentially save you from some uploading. As Google notes, they will "scan your collection and quickly rebuild it in the cloud."
The scanned and matched music will be streamed back at 320 kbps. Also worth noting, Google Music was, and remains available for free. All said and done, this seems like a win for existing Google Music users and it should also be enough for those who held back because they had large music collections and were turned off by the long upload times.
In fact, the one question that seems to remain is whether or not these matched tracks will count against your 20,000 track limit. We suspect they do, however given you are not technically uploading any music, it would be nice if those were not counted towards the 20,000. Of course, we have to wonder how many users are actually uploading 20,000 tracks.