Do you think that Xsyon should have two, or more, servers? Why or why not?
Out of personal belief, the reason I would say no is for multiple reasons.
For starters, a single consistent world has far more player standing and actions ripple in it from player decisions. EvE, for example -- everyone who played EvE from 2006 to late 2009 knew who GoonSwarm were. They developed a reputation that stretched out across a single, persistent universe.
The same is true now. AAA, BoB, etc. Their actions and the actions of players effect everyone, consistently.
If you split the servers, it will become " Well our best tribe can pwn your best tribe! " without any real way of knowing ( this being after Prelude, of course ). It takes a wide variety of people to make a sandbox MMO work successfully, and Eve has proven this that it DOES work.
The second reason is for population reasons. Rather than split up a community of less than 10k players on to two servers, it would be more meaningful to keep that community together, and only expand to two servers IF the active-player count rises beyond what is acceptable for a single server to handle. And even that can be debated about, pending the other reasons why a person would say no.