I think they will eventually implement something like this, I don't think it will be very fancy, or glamourous, but I don't see why a 24 man raid is not possible. It may be a huge grind though, to get the raid going otherwise it would be too easy (possibly).

When they do release it, it will be a glorious thing, and I don't think it will be limited to FC, but still if you have 24 people it would be a blast to do

-Tari