Found this in Wikipedia:
In January 1994, Paul McCartney was given two tape cassettes by John Lennon's widow Yoko Ono, which included home recordings of songs Lennon never completed or released commercially. The songs on the tape included the eventually completed and released "Free as a Bird" and "Real Love", in addition to two other songs "Grow Old With Me" and "Now and Then". In March 1995, the three surviving Beatles began work on "Now and Then" by recording a rough backing track that was to be used as an overdub. However, after only two days of recording, all work on the song ceased and plans for a third reunion single was scrapped permanently.
According to Paul McCartney, George Harrison "didn't want to do it," possibly because new verses would have had to been written. Producer Jeff Lynne reported that "It was one day – one afternoon, really – messing with it. The song had a chorus but is almost totally lacking in verses. We did the backing track, a rough go that we really didn't finish." An additional factor behind scrapping the song was a technical defect in the original recording. Like Real Love, a 60 cycles mains hum can be heard throughout Lennon's demo recording. However, it was much louder on the Now and Then recording, therefore making it much harder to remove.
Throughout 2005 and 2006, press reports speculated that McCartney and Starr would release a complete version of the song in the future. On April 29, 2007, it was reported in the Daily Express[1] that the song may be released to coincide with the Beatles catalogue being released for the first time via digital download. At the time of this writing, the only available recording of this song is Lennon's original demo(complete with the "electronic buzz" embeded in the recording). The overdubs added in 1995 by the other surviving members have yet to surface.
In 2007, reports circulated[2] that Paul McCartney was hoping to complete the song as a "Lennon/McCartney composition" by writing new verses, laying down a new drum track recorded by Ringo, and utilizing archival recordings of George Harrison's guitar work.
http://en.wikipedia.org/wiki/Now_and_Then_(song)
There may be something about it in Keith Badman's
The Beatles After The Break Up, too, but I'm not at all sure. The surviving demo, even leaving aside the loud tape buzz, doesn't strike me as being at all promising.
