...Simplify Media/Music shut their doors to new customers in March. They allowed you to stream your own iTunes library to your iPhone/iPod via 3g/wifi, as well as sharing it with a few friends. When they announced they were closing their doors they said they'd provide the service for the next three months - so mid-June - but that they couldn't share their plans for the future. Friend sharing stopped straight away.
See
http://www.simplifymedia.com/blog/
I'm really hoping that this is the "iTunes in a cloud" announcement, and that some of the people who have spent their time and money creating businesses that Apple are shutting down/replacing/embracing are making a decent amount of cash out of it!
TT