But the Beatles actually appeared in live-action at the end of the film. I remember Paul reprising the "I've got a hole in me pocket" gag.
Yes but that's basically a cameo.
But it does constitute some involvement in the film.
Not sure why this is such a point of contention, but wikipedia does seem to back me up that the Beatles had little to do with it...
Because "little to do with it" is not "nothing to do with it." What you said before is that you thought they had no involvement at all, and any involvement is more than zero.
Forgive me. Don't know what I was thinking when I wrote that. Guess I was thinking they could somehow use motion-capture in 2D animation, but now thinking on it, it sounds really silly.
They've been doing 2D motion capture since the earliest days of animation. But they did it by hand and called it rotoscoping.

Great comments about animated characters btw. I find it interesting that in doing what they did, they actually made the classic characters more marketable, whereas the more modern versions are basically a wash. I honestly can't see the more modern versions be more popular than their classic counterparts.
Well, "modern" is relative. 1947 Daffy Duck, for instance, was pre-Chuck Jones Daffy Duck. He was more of a goofy lunatic a la Woody Woodpecker, and Jones hadn't yet developed his more successful persona as the vain incompetent whose arrogance was his downfall. Similarly with Bugs -- Jones refined his personality and made him less a nutcase who did randomly mean things to people and more of a comic hero who only struck against those who mistreated him or others, but struck with ruthless wit and took total control of the situation. And their modern character designs are basically the ones perfected in the '50s alongside their personalities. So their 1947 versions hadn't yet matured into their most successful incarnations, the ones that have defined them for well over 50 years now.