Citing "a wide variety of insider sources," Michael Robertson, former CEO of mp3.com, claims that this speculation is correct. He says that instead of moving to a subscription-based model, Apple will indeed leverage the technology and resources of Lala to allow users to stream their music libraries from a remote server.
It will be interesting to see if Robertson and other analysts' speculations are correct. There are certainly some technological hurdles to surmount in letting millions of iTunes users stream billions of songs – my own music library is nearly 40 GB, which is twice the default data allowance on MobileMe – but licensing issues seem to be even thornier. While Robertson says that "...because users are in possession of the materials no new licenses are required from the record labels or publishers," for streaming content, I'm going to go out on a limb and say that your friendly neighborhood RIAA will disagree. However, if Apple can indeed make this streaming service happen, it will be a huge win for them, and more importantly, for us users.