I agree with SOB - We need more people to jump into XI PvP to start it up, not just sit AFK, to actually play, sitting AFK does not help at all. (no offence) I know it's easier to just join a different server where there are players, but if we work together and make XI Server a known server, people will go in there by themselves so we aren't always needed no more to start things up.
As for the CO-OP, don't get rid of that, there's some players that prefer CO-OP over PvP, and especially how it goes now, if people don't help fill the PvP Server, I go to the CO-OP XI too. Or other servers. I spend a lot of time trying to get people in our server, I bug them on Steam, X-fire, TS, the shoutbox... It's more so that non-members follow me in. And yeah, there are different time zones, people have work, school, whatnot.. But I am online for at least 8 hours a day, big time span.
So, let's work together guys! Let's make this PvP Server as popular as the COD4 MW2 Server!