Apple is allegedly set to announce plans to launch an online music streaming service similar to Spotify soon. How soon? As in next month’s Worldwide Developer Conference, according to several online rumors.

Speculated to debut on June 7, the service — if it is coming — would likely be based on Apple’s purchase of Lala six months ago. A note at the Lala web site (http://www.lala.com) says “The Lala service will be shutting down on May 31” and “unfortunately, we are no longer accepting new users.”

Lala — which offered “the first and only free fully licensed service to instantly provide anywhere web access to an existing music library such as iTunes” — was purchased by Apple earlier this year. The goal is probably to allow Apple to implement a new iTunes feature that would allow users to stream their purchased media content remotely. In fact, rumors of such a service surfaced earlier this year.

Purportedly, the service would allow iTunes shoppers to build up a digital video collection (music, movies, TV shows, etc.) without having to worry about the intensive storage space involved. iTunes Replay would, per the rumors, stream music, TV shows and movies purchased on iTunes, so you wouldn’t have to download them after purchasing, freeing up hard drive space.