In a Paul McCartney interview by Mojo Magazine the expected release to iTunes is sometime in 2009, and more important Apple and Apple Corps are agreeing it has to be done right.
In a Chicago Tribune interview in late 2007, Paul McCartney thought the release to iTunes would happen in 2008 as it was stated that the delay of early Beatles’ albums appearing on iTunes may be due to the time it takes to digitally remaster the catalog rather than the assumed legal battle between Apple Corps and Apple, Inc. The project appears to have taken longer than thought.
The Mojo article also says that all the Beatles albums, including Yellow Submarine, Magical Mystery Tour and the Past Masters albums, have been remastered, but not The Hollywood Bowl. Two albums, Rubber Soul and Revolver, will be available in three mixes, mono, original stereo and the 1987 stereo rebalances. No 5.1 mixes are planned for any of the albums.
What Goes On has the report on the interview
It may actually happen
Currently, the individual works of each of the former Beatles, John, Paul, George and Ringo are available on the iTunes Store.