Thumbplay launched an invitation only beta of their cloud-based music streaming service back  at the beginning of February and today have opened up Thumbplay Music beta to all.

Thumbplay is a free BlackBerry download and is currently available on BlackBerry App World for the BlackBerry Storm, Storm2, and Bold 9700.

Thumbplay does offer a premium service which offers on-demand access millions of songs and the ability to play them while offline.  There is a free 3-day trial, however, it will cost $9.99 after that.