I didn't like the movie very much. I pretty much agree with Ebert and Dave Poland's reviews.
Spoilers follow...
To me it was just another washed out looking illogical Spielberg SciFi film like the other ones he's made after the end of the millenium.
The characters were cliches (the flawed dad, the rebellious son, the quirky, precocious daughter). I didn't think any of the lead performances were especially terrific. They were all not very natural. The ex-wife and stepfather character seemed overly perfect and almost kind of unfair to the Cruise character. Perhaps that was intended, but it wasn't fleshed out.
The son was pretty much a dumbass. I didn't understand his motivations at all. The whole family dynamic seemed set up just for the purposes of the movie.
The 9/11 references (ashes, city in ruins, people video taping the chaos, "have you seen this person?" flyers, etc.) were unsettling (Maybe on purpose, but for what purpose seemed unclear. The other political references by Robbins near the end are also questionable).
The movie just wasn't fun. It's very tense in places, but just not fun. It's almost similar to Aliens in the despairing sort of mood that's presented, but I actually cared about the characters in Aliens. The characters here basically run from setting to setting doing the usual action movie stuff. I wanted to have a good time with the movie, but it just wouldn't let me. The movie felt disjointed and didn't flow extremely well. Maybe it was a chaotic feeling that Spielberg was going for, but I think maybe he could've given off the mood of chaos without making the movie itself seem jumbled.
I wanted to have shivers run up my spine during the movie & feel creeped out, feel the suspense, and the excitement, but I just felt tense and uneasy.
As I mentioned the logic in the movie is extremely faulty. Do the aliens come down in a different form when they slide down in the lightning to the tripods? Why do they want to take over Earth in the first place? Why are they able to be defeated so easily if they have been watching the planet for years? Can the aliens not see things? Cruise and Fanning were not particularly shrouded when the aliens were in the basement with them.
Another logic problem was near the end when Cruise and Fanning are in the basket and Cruise explodes the grenade. They all would've been so dead that close to the explosion. Also convenient is how the basket falls apparently easily to the ground from a pretty extreme height.
The end of the movie just fell flat. Too many coincidences, especially the son surviving.
When it was over I just left feeling empty. It didn't give me anything to hold onto.
"The gods who nurse this universe think little of mortals' cares. They sit in crowds on exclusive clouds and laugh at our love affairs. I might have had a real romance if they'd given me a chance. I loved him, but he didn't love me. I wanted him, but he didn't want me. Then the gods had a spree and indulged in another whim. Now he loves me, but I don't love him." - Cole Porter