(I'm mostly responding to Lisa below. I wrote all of this earlier, but I've been running around at work and away from an Internet connection. I see that Jeff has also responded. I'm off to read those. I'll probably respond more later.)
I do think that the closest parallel situation is with Tarkovsky, not with Godard.
The best short appreciation of Tarkovsky's Mirror can be found here: http://www.reverseshot.com/article/mirror
"Each cut is an event, a moment not simply to collide images but also to layer the collage of the film: picture and sound, married and abutted, proffering new sights, new landscapes, new emotions and new realities in light. Andrei Tarkovksy’s Mirror is full of such event-cuts, each defining or sensing the cohesive whole of the film, like its maker, as discrete moments hung together through time, however disparate and dispersed its instances, like his limbs, may seem. To whittle a life into a film, as Tarkovsky attempted, may be impossible. However, Mirror does not attempt a picture of an entire life: it offers metonymic moments of a life caught across a celluloid timeline." - Ryland Walker Knight
Replace the word Mirror with Tree of Life and the name Andrei Tarkovsky with Terence Malick.
Tree of Life could never be someone's high school poem or someone's art school thesis. It is much too masterful for that. There's no doubt in my mind that this is a work of a professional. And think that should be obvious to anyone whether or not they've ever hears of Malick or whether or not they enjoy Tree of Life.
Why is Tree of Life important? Because it pushes at the boundaries of what narrative film is and can be. Is this for the masses? No, probably not. And not ever. Still, Tree of Life will be remembered long after Hangover 2 has been forgotten.
One neat aspect of film is that it absorbs all of the arts. Editing images is distinctly analogous to editing sound (read Murch on this). It's about rhythm. I don't think that it's best to compare Tree of Life to Joycean novels or modernist poetry.
It's better to compare it to a symphony, with pattern and variations layering on top of one another, stating a "theme" and circling around it in new ways, re-stating it and re-interpreting it as the whole moves forward and builds toward a satisfying resolution. It's about experiencing and getting lost in the "music" rather than following a traditional "story."
Sorry that you're still bitter about that high school poem rejection, Lisa, but don't take it out on Malick.
[I did love your post and the entire stepping up of playful aggression. Bravo.]