The CEO of the Recording Industry Association of America Hilary Rosen believes Apple's music downloading service has the potential to "do for music sales what the Walkman did for the cassette," she told the New York Times.

The litigious RIAA appears firmly in Apple's corner, as the company prepares to announce its service today. Rosen believes Apple to have struck an "industry-friendly balance". The New York Times requires readers to register in order to access its content.

"It has compatibility with a hardware product that is elegant and easy to use," she said.

Digital media analyst Phil Leigh of Raymond James Associates said: "The service will raise the consciousness of the public that there are legitimate alternatives to KaZaA. It signals the transformation of Apple into a digital media company. Within ten years, we'll look back and say this is when it mutated."

Apple is widely expected to introduce new model iPods when it announces its music service. Hardware remains its main business focus. IDC analyst Roger Kay believes Apple is equipped to handle the challenges of entering a new business arena, telling CBS MarketWatch: "I have no doubt that Apple can manage that sort of (technological) universe. It's a high-risk strategy, but not one that necessarily won't work."

Wall Street is beginning to take an interest too. Despite continued soft trading in its stock, Friday recommended Apple shares as a "Buy". "A long strategy offers traders a nice chance for a profitable trade," the report said.

US music industry bible Billboard last Friday claimed that Apple's service is an a la carte download store - like that of rival Liquid Audio - that is built into iTunes. No subscription is required for the service, and tracks are expected to retail for an average of 99 US cents. Once purchased, tracks are transferred to the iTunes music library, and automatically synched to the iPod. Content can also be burned to CD. Credit-card information will be stored in the store's shopping-cart system so the consumer does not have to re-enter the information for each purchase.

Apple will announce the facts behind the rumours during a special event that begins at 6pm (UK time).