Had the Beatles continued after '69, what would have been their niche?

Most likely they'd have had Phil Spector as producer on a late 1970 or 1971 album. George and John were just so high on Spector at the time. Paul probably would have consulted with Spector on string arrangements he might want, but otherwise Paul would have probably be the de facto producer of his own songs on the album in this scenario, with Spector working much more closely with the other three. You'd have Clapton playing guitar on one or two of George's songs (so he didn't have to teach the parts to John), and Billy Preston in the mix somewhere as well.

 

The continuation of Get Back: Get Settled Down^^

 

I'm late to the party on this thread but my answer to the question would be the Beatles would go on occupying the niche of being the biggest band in the world.

 

Maybe a tour in 1971 and a movie ('A Hard Day's Night 2') one year later would had been interesting, too.

 

I figure they probably would have sounded like America until they did the music for a James Bond film. Too bad most people remember them mainly for their disco phase.