WvW in GW2 is nice for some time but then you got like 2 maps and no real objectives or reward for doing it. You don't get to new map if you win or anything. Also since you can switch server practically any time you want, competition between servers is pointless, even if populations were evenly matched by some miracle.
It's basicly problem with every mmo I know, even EvE-o. Everything is so care-free. Just get together 50 guys, go bash bunch of newbies (for no obvious reason than having guild event that night) and chest bash yourself for being so good and awesome guild. It doesn't really feel that you actually achieved something.