GW2 has a system of 'downscaling' meaning that every max level scales down to the level he is in. This should allow max levels to have fun in the lower zones.
one small problem: there is little incentive for them to do so. In fact: travel costs alone make it not worth it for many.
So while i was hoping to see many max levels everywhere, I just see them in the highest level area Orr, nowhere else (except major city and pvp zone).
GW2 is a wonderfull game to wander about alone in... IF there are other people around.
Should you decide to go for it, than keep swapping servers till you find one that has people in he zone you're in (server swapping is free for now, and has a 24h cooldown).
Officially the servers are very full and crowded, but in reality I find them to be empty an awfull lot of times. Or better: the mid level area's are.
Many say it isn't true that a lot of players simply left. I can't tell for sure. All i know is that if they are still playing, they're not in the lower zones.