Excellent... It's Just That Simple (Entire review contains spoilers... Please pass this review up if you haven't seen it.)

Rating: Null/10 (19 May 2003)

I thought this was an excellent addition to the Zion Mythos (I guess I'm terming the Matrix World much like H.P. Lovecraft...)
A common comment I see about this film in boards is that the mystery of the Matrix that was so boldly introduced in the original is gone, leaving people not as psyched about this film as the original. That's all fine and well for this film, but the depth of the film more than makes up for this shortfall, as the details enter areas the first film could not.
For example, the emerging conflict in Zion (pre-destruction): those who believed in the prophecy that would later betray them (Counselor, Morpheus, etc.), as well as those who believed that humans needed to outthink the machines (Locke, Most Ship Captains, etc.) was refreshing to see. Not everyone agreed with the way Morpheus did things outside of Zion.
In addition, the machines themselves had their own dichotomy, in which the programs of the Matrix had different levels of existance: the active programs, such as the Architect, the Agents, etc., who all exist within their duties in the system; those programs marked for deletion, such as the Oracle, Seraph, and the Keymaker who all have 'outlived' their usefulness in the system, and applications, such as Merovingian, who perform tasks for the active programs, but not at the same level as the other programs, as he mentions his more illegal activities in the Matrix, and as can be seen with his guardians (The Twins) shooting Matrix Agents in pursuit of them.
In addition, you also have viruses, such as Agent Smith, who is now outside of the mainframe, who exists now to destroy the entire system, with the humans inside of it as well, as can be seen with his assimilating of clones made of human participants (Cain) and digital participants (Agent Thompson). This latter part of the machine hierarchy will be indeed interesting to see in the Matrix Revolutions as Agent Smith now acts as a threat to both the source code as well as Neo and the humans.
The most interesting aspect, however, is Zion, where the Prophecy and the Oracle referred to the Human City as a secret, but the Matrix more than allows the city to exist to serve it's ultimate purpose; to revise the Matrix code with The One as it's catalyst, which introduces the division problem: what really is the boundary between the Matrix and the real world? What if Zion is a part of the Matrix itself? Neo's little stunt with the sentinals introduces that thought: that perhaps Zion itself is an illusion, and there is no real world.
In any case, the third chapter to the trilogy should deliver much of the same thing. It was amazing to see this film reveal so much, but I see the third film being taken like "Return of the Jedi", or "The Return of The King", as people will see it just to conclude the story, but still, it should be an interesting chapter nonetheless.
Overall, The only bad things I've heard from others is that the action scenes seem too video-game like, and that the love scene in Zion was too damn long (which I thought fit in as a mental shift perfectly). I think if you expected to see something as mindblowing as the original, you may have been disappointed. But if you're an action junkie, you'll totally dig, and if the drama/philosophy is only what your after, this more than blows the first one away.