I'm 16, so no way do I have kids, but I have a feeling that one day my kids will be Beatle lovers!
But, I did get my 10 year old cousin into them last summer. I just played him a song, Day Tripper I think, which he liked, and then he asked to hear Yellow Submarine, and it just kept growing from there. I think he likes them a lot, but I don't know about obsessed.
Also, my 3 and a half year old niece likes 'em too! My whole room is decorated Beatles, so every time she comes over she asks me "Hey Julia, you wanna listen to the Beatles?" And then I showed her who was who just by first name for now, and now every time she's over she asks me to name each one in every single picture in my room, and god do I have a lot of pictures. One time Kansas City was playing and she's like "Is that Paul?" I'm like "Whoa, yeah, actually you're right!" She's very smart for her age. We watched Help! too, and I think she really liked it. She actually put it together and knew it was the Beatles in the movie. And before she went to bed she's like "Hey whata the Beatles doin?" I'm like "They're probably going to bed now, too." Haha, that's funny. Beatlemaniac in the making.