I would love to see a Beatles biopic. Maybe have some of the same cast as the Lennon biopic "Nowhere Boy" that came out recently.
Aaron Johnson as John Lennon (reprising the role from "Nowhere Boy")
Thomas Sangster as Paul McCartney (reprising the role from "Nowhere Boy")
Skandar Keynes as George Harrison (Edmund from "Chronicles of Narnia")
Matthew Lewis as Ringo Starr (aka Neville from "Harry Potter"...a little bit out there but he has the same kind of awkward look that Ringo has)
Michael Sheen as Brian Epstein, the group's manager
Paul Bettany as George Martin, the group's record producer
Carey Mulligan as Cynthia Lennon (the movie could use a female lead...why not John's wife?)
Don't know who would play Yoko. The principles should all be played by actors in their early 20s so they can play the roles during the entire span of the band's career from 1960-1970 and then some.