There are opinions galore out there, so I'll keep my own petty ramblings as short as possible (a few spoilers ahead).
It was fun. I won't deny the fact that I enjoyed the ride (most of the time). Disliked: Zion and the dragging scenes of pseudo-philosophical dialogue. Liked: Kung-fu and the campy humor (some intentional, some not).
Were “bullet-time” or special effects used in new, mind-bogglingly creative ways? No. Same ideas, but with a bigger budget, more computers and explosions.
If the Matrix can be summed up as the “brain in a vat” story, The Matrix Reloaded is the “cog in a machine” story. Oooo, what a twist.
My prediction (a bit of a long-shot) for the third film is a Ghost in the Shell-type resolution with Neo and Agent Smith merging consciousnesses (dying in the process), to form a new, neutral consciousness which allows machines and humans to see the error of their ways and get over this whole 'enslavement' hang-up. Ah, but preceded by 2 hours of more flying, kung-fu, guns, robots, bigger guns and bigger robots.
What I'm hoping for is those two action-packed hours and then: Neo dies. Fade to black. Fade in on computer screen. Text: 'Wake up Neo…' Fade to black. Roll credits.