SkySYNC has publicly released a beta of their upcoming SkySYNC service. The service is a pretty simple concept where you upload all your music to their cloud servers and they they let you WAP stream them to your BlackBerry. I tried it for a few songs but it took forever to upload and the streaming did not always work on my Bold 9700. Bla1ze over at CrackBerry seems to be having similar issues with larger libraries of music.
I wish somebody would create a service that would let you stream your music to your BlackBerry directly from your PC. I think that would work better and give you more control while not having to wait to upload everything to the cloud. Still if you have been looking for a solution like this check it out at www.skysync.fm