I think Rod has pegged Wall-E very well--read it all. But 'ware the spoilers, which are extensive. And this commentary is ever-so-slightly spoilery, too.
It is a great film, and, like Ratatouille, a risky one. As with all things Pixar, it is technically flawless, a film that repays multiple viewings just for the artistry alone.
On to themes.
It is a movie about tradition, connecting with others, being distracted by Things, the human spirit, love, using technology rightly (as opposed to casting it aside altogether) and the indispensibility of the natural world.
And it does so with less dialogue than any other film you will see this year.
To dismiss it as kiddie-friendly environmentalist propaganda only--and ironically--proves how disconnected some people have gotten, especially those who identify themselves as conservatives.
If conservative "thought" requires you to kick the film away with a knee-jerk, then you are welcome to it. Enjoy life in the solipsodome.
Such as it is.
Let me just add, in my patented Certainly Reading WAAAAY Too Much Into It Review Mode that I think that Wall-E also makes two other subtle nods.
First, to the importance of both Moms and Dads in making things work. Both Wall-E and EVE have to protect the plant, and without both, all would have been lost. I don't think that one goes too far afield.
Second--and all aboard for Conjectureville--I think there is a Jesus/baptism metaphor in Wall-E's encounters with Mary and John, both of whom the robot wakes from their waking, disconnected slumber.
"We have a pool?"
They go to the pool and are changed. They feel real joy for the first time in their lives. They ignore the "no splashing" command from the robot supervisor. They rescue the falling children when the Axiom tilts. In other words, after going to the pool, the two of them stay in Reality--the True, the Good and the Beautiful--and never return Plato's cave (to homogenize my metaphors). Siloam, anyone?
Yeah, ok--I'm the guy who can read a "Peter vs. Judas" subtext into Falling Down. Still....
Do not let my hallucinatory Christianist godbothering deter you from seeing it. The film has something for anyone of good will.