Somehow I missed this great review of WTWTA by Marshall Fine when it first appeared. It talks about the way the film portrays childhood, but doesn't get quite as, um, morose (too serious? or can one be too serious about play and childhood?) as my earlier interpretation. Both views speak equally to the greatness that is WTWTA. This isn't a movie that is easy to pin down, that's for certain.
...Jonze has made a career out of subverting genres and expectations, whether in “Being John Malkovich” or “Adaptation.” In this case, Jonze and Eggers have written a film that truly captures what it’s like to be a 10-year-old, in all its mood-swinging glory. This film is fueled by imagination, not driven by plot or built around structure. It’s a film about play and the sudden shifts it can take when someone gets upset or hurt or hatches an unexpected idea.
Beautiful, and absolutely correct.