Which way will a future expansion take us, down to the Underfoot, or up to the Planes of all the Gods?
Probably neither of those. In a recent webcast, the developers said the next expansion would take place somewhere that hasn't been focused on in either EverQuest games: http://eq2wire.com/2012/05/25/the-f...ire-transcript/ There are a few threads already out there with speculation on where that may be.