The us-site is stating a 6-month free streaming (after 6 Month limited to 10hrs a month with ads), here in Germany, the experience was more like: get 30sec of that song or suscribe to a music-pass (first month free).
To check, if i can get rid of Spotify (no WinRt-app so far and on Wp 7.5 te app isn't what i would call reliable), i suscribed, but i do have problems with streaming and playing songs from sd-card, when connected standby kicks in.
And finally: The app isn't very user friendly, i can't think about managing a nice collection of music with it.