Heya~ You're name sounds familiar, but I can't say I know exactly who you are. Nice to meet you (again?)!
I'm actually a part of Nephilim, joined a couple years back a little after my brother Jawat did. There's a good amount of people on the LS at times, though the past couple months have been a bit slow because we've cut back on weekly scheduled events (we're trying to start them up again). If you want to see who's still playing from the LS, you can always check the forums~ (at least, I think you can; not sure what you need admin permission to view/post in) http://nephilim-x.com/forum/
As for the server population, I can't say that I've noticed any major changes (though, I fish a lot, so I'm biased because I'm usually all by myself in deserted areas, heh). I hear some concerns about lower-level areas being a bit less crowded, but there's still plenty of people taking up lots of jobs. Plus, even if there are less people, it helps to combat over-crowding in popular camps. There are also alternatives now such as experience points increases in duoing, trioing, etc., so even if you can't find a full party, you're still good to go~. At higher levels, you can now also get experience points doing things like Besieged or Campaign, which don't actually require the formation of parties.
Of course, once you hit level 60+, you won't notice the population change at all, especially if you level in AU areas. Hoo-boy, are those ever popular...
Anyways, hope that helped a bit! Take care~