The reason VG has so few subs is because they released an unfinished, buggy game. In spite of that they got a lot of understanding from the community resulting in an unusually low amount of hate for doing so.
I think VG will be just fine because it's fun and once it's finished it'll likely be the most immersive MMORPG on the market. I don't know what the sub numbers are but at peak times all the servers read as high pop and even at lower pop times I haven't had much trouble finding other people to play with, not to mention there is so much more to do than just kill stuff if you can't find groups. Dead in 18 months? I highly doubt it, VG will be around for a while, I say it'll still be running long after LotR has shut down.