Many people have been driven away from Cyber Nations due to Perma-ZI Joker. Just go to LW forums, you'll see a whole club of them. Although a lot can be blamed on permanent ZI, its actually just the way the game works.
Example. Any player who starts playing in 2008 has an incredibly narrow chance to pass up a player who started in 2006. Looking through stats, only 4 of the top 50 nations were founded in 2007. The rest were made in 2006. So, looking at this, its safe to say most at top are there due to seniority and accumulating strength over time. Even I felt this when starting in late 2006, that I would never reach the rank of those who started when the game did. As time goes on, this possibility of moving up to the top ranks becomes just that much more narrow.
And its one of the most noticeable things about the game.
Its why so many people join, and then leave. They notice how slow it is, and then take a look at the top nations, and realize they're ages away from reaching that point. And when they do, those nations will probably be even more ahead of them. Then others just quit because it seems boring. Then others quit because they don't feel like joining an alliance, so they'd rather just die.
Combine the game mechanics with the Elitist style of playing, and you realize CN has such a small potential for growth its ridiculous. So, having looked at this, its easy to say that most of the long-lasting members are going to be ones from 2006 to early 2007. And these people are dying off, and not being replaced. The way the game is set up is just destined to an end when a certain group has held on for so long that they can no longer be knocked off, and there is no chance for a comeback.
I'm highly expecting CN to either end or restart sometime later in 2008. Then again, I'm sure some other people thought the same in 2007, so who knows.