The new War of the Worlds shows Steven Spielberg at his best. It's the only one of the summer's blockbuster's so far that has teeth and guts: underlying its impressive fx-driven set-pieces is a genuine emotional core.
I thought that Spielberg's middle-class, crowd-pleasing sensibility was particularly unsuited for the "dark" sci-fi material of A.I. and Minority Report, but in War of the Worlds he successfully combines the apocalyptic, doom-laden tone of those films with the comic-horror approach of Jaws. As in Jaws, Spielberg has woven a hard-boiled sense of humor into what is otherwise a truly terrifying movie.
Another problem I've had with a lot of Spielberg's recent movies is that they have weird subplots or rather sub-themes about (absent) fathers and sons. Spielberg has a kind of obsessive fixation with bringing up father-son issues in all his movies, whether or not the movie really needs them. It makes sense to deal with bring this up in a movie like A.I., which riffs on the Pinocchio story, but the father-son stuff in Catch Me If You Can, Minority Report, and The Terminal seems out-of-place and forced. Spielberg is a master of a wide range of filmmaking tricks and techniques, but it sometimes seems like the only way he knows how to add emotional and psychological complexity to his characters is to give them a father-son issue to deal with.
The father-son stuff is back War of the Worlds (although it has become father-son & daughter), but here it works perfectly, probably because it's now the focus of the movie and not just a sub-theme. I figure if you're going to deal with an issue, it's probably better to tackle it head on than to leave it sitting uncomfortably off to side.
Playing the father character, Tom Cruise is pretty darn good. I'm not sure why, but Cruise is a lot better when he's playing opposite children than he is playing opposite adults.
One problem with casting Cruise, though, is that it's almost impossible for the audience to react to him as an "everyguy". It doesn't ruin the movie by any means, but it sometimes gets in the way of what Spielberg is trying to do and ends up undermining some of the intensity and suspense.
A bunch of quibbles and spoilers follow...
I thought War was really good up until the third act, when things don't go wrong exactly, but they do stop working at the high level of the first 2/3rds of the movie. Spielberg tips his hand too early when he introduces the Tim Robbins character. And Robbins's over-the-top style is completely different from that of every other actor in the movie.
And Spielberg seems to have run out of ideas for big set-pieces at this point, so he starts ripping himself off: there's a sequence that's right out of Jurassic Park and other scenes and images that are taken from A.I. and Minority Report. All this stuff works okay--better, in fact, than it does in the earlier movies--but I wasn't exactly thrilled to see it again and I wish he had come up with something new.
As Steve Sailer pointed out, the ending, while faithful to H.G. Wells, is a little anti-climactic. But, more than that, it's kind of lackluster sci-fi. The aliens in the movie are selectively dumb--not as dumb as the aliens in Signs, but they're close. They can travel through space and build super-weapons and plan a huge world-destroying invasion, but they haven't figured out how to analyze water samples for harmful microbes. (I suppose this makes sense if you see the movie as an allegory that invading armies will be undermined by the pre-existing conditions in the places they invade, but, again, as sci-fi, it's pretty weak).
Finally, Spielberg can't resist having as unambiguously a happy ending as possible. Cruise's son, who we assume is dead, turns up alive and safe at the end of the movie. Spielberg's issue with endings deserves its own post. For now though, I'll just say that he really makes it hard to respect and remember all the genuine, wrenching emotional stuff that happens during his movies when he's so willing to provide cheap, not to mention unbelievable, Hollywood endings.