While I liked the first film, my overarching reaction was much like my reaction a few years later to the first X-Men film: that it was set-up for an even more interesting second film. The second X-Men delivered on that. The second Men In Black didn't. (Plus it wasted a genuinely good performance by Will Smith, showing how world-weary J had become. Playing world-weary is a tough acting job for someone young. Even Orson Welles -- who was 25 when he made Citizen Kane -- had trouble with it.)
But time travel? One of my story loves. Clever casting? I'm all over that. Just the whole look and camera work of the MiB films? I truly like that: Barry Sonnenfeld was born to shoot this series this way.
Now I just have to hope the story's indeed compelling. Considering what most intrigued me about MiB II was something that turned out not to be true about the film at all*, I want what the filmmakers actually came up with here to be worth my time.
* Since a scene in an early cut of MiB II had been set on the roof of one of the World Trade Center towers, a rumor went out that the ending involved a slew of alien spaceships folding themselves out of the WTC, much like the craft hidden in the World's Fair complex in the first film. The rumor went on to say that the film's post-9/11 reshoots also shot footage of the Chrysler Building, implying that special effects would be redone so that the alien ships would be inside that building. Again, none of that was true. Though it makes it feel more right that the third film does use the Chrysler Building...