Oh, no. Every server is far from dead. Balmung ranges from 25-30k pretty consistently and Gilgamesh is only slightly behind that. Unfortunately, the only way to get onto these servers is by transferring, which costs $18 USD. You can try making a new character in the every early morning as they sometimes open, but it's rare. With Christmas, New Years and the 3.5 close though, you might get lucky since not as many people will be around. I know a lot of people who jumped from quiet servers onto Balmung and they said it felt like a different game.

Something to keep in mind. Gilgamesh is considered the unofficial raid server. If you have any Savage aspirations, it may be better there. Balmung does have a growing raid scene, but it more casual focused. It's also considered the unofficial roleplay server. So you'll generally see people hanging around most major cities.